[llvm-debuginfo-analyzer][DOC] Convert 'README.txt' to markdown.

As part of the WebAssembly support work
llvm#85566

The README.txt is a bit odd since it only lists issues and
problems without talking about what works. It’s also hard
to read on the GitHub web view.

- Address more feedback in relation to the correct Use
  of monospace.
- Keep DWARF, CodeView, PDB as plain text.

Author: CarlosAlbertoEnciso

llvm/tools/llvm-debuginfo-analyzer/README.md

@@ -10,25 +10,25 @@ Use a standard (or LLVM) ``map`` with ``typeinfo`` (would need a specialization
 to expose equality and hasher) for the allocators and the creation
 functions could be a function template.
 
-### Use a ``lit test`` instead of a ``unit test`` for the ``logical readers``.
+### Use a **lit test** instead of a **unit test** for the **logical readers**.
 **[D125783](https://reviews.llvm.org/D125783#inline-1324376)**
 
 As the ``DebugInfoLogicalView`` library is sufficiently exposed via the
 ``llvm-debuginfo-analyzer`` tool, follow the LLVM general approach and
-use ``LIT`` tests to validate the ``logical readers``.
+use ``lit`` tests to validate the **logical readers**.
 
 Convert the ``unitests``:
 ```
 llvm-project/llvm/unittests/DebugInfo/LogicalView/CodeViewReaderTest.cpp
 llvm-project/llvm/unittests/DebugInfo/LogicalView/DWARFReaderTest.cpp
 ```
-into ``LIT tests``:
+into ``lit`` tests:
 ```
 llvm-project/llvm/test/DebugInfo/LogicalView/CodeViewReader.test
 llvm-project/llvm/test/DebugInfo/LogicalView/DWARFReader.test
 ```
 
-### Eliminate calls to ``getInputFileDirectory()`` in the unit tests.
+### Eliminate calls to ``getInputFileDirectory()`` in the ``unittests``.
 **[D125783](https://reviews.llvm.org/D125783#inline-1324359)**
 
 Rewrite the unittests ``ReaderTest`` and ``CodeViewReaderTest`` to eliminate
@@ -47,7 +47,7 @@ Add the ``PRIx64`` specifier to the printing code (``format()``).
 ### Remove ``LVScope::Children`` container.
 **[D137933](https://reviews.llvm.org/D137933#inline-1373902)**
 
-Use a ``chaining iterator`` over the other containers rather than keep a
+Use a **chaining iterator** over the other containers rather than keep a
 separate container ``Children`` that mirrors their contents.
 
 ### Use ``TableGen`` for command line options.
@@ -62,10 +62,10 @@ Change command line options to use ``tablegen`` as many other LLVM tools.
 The more idiomatic LLVM way to handle this would be to have ``find``
 return ``Optional<ValueType>``.
 
-### Pass references instead of pointers (``Comparison functions``).
+### Pass references instead of pointers (**Comparison functions**).
 **[D125782](https://reviews.llvm.org/D125782#inline-1293920)**
 
-In the ``comparison functions``, pass references instead of pointers (when
+In the **comparison functions**, pass references instead of pointers (when
 pointers cannot be null).
 
 ### Use ``StringMap`` where possible.
@@ -78,26 +78,26 @@ because the key is not a ``std::string``.
 Replace the use of ``std::map<std::string, ValueType>`` with ``StringMap``.
 One specific case is the ``LVSymbolNames`` definitions.
 
-### Calculate unique offset for ``CodeView`` elements.
-In order to have the same logical functionality as the ``DWARF`` reader, such
+### Calculate unique offset for CodeView elements.
+In order to have the same logical functionality as the DWARF reader, such
 as:
 
 * find scopes contribution to debug info
 * sort by its physical location
 
-The logical elements must have an unique offset (similar like the ``DWARF
-DIE offset``).
+The logical elements must have an unique offset (similar like the DWARF
+``DIE`` offset).
 
-### Move ``initializeFileAndStringTables`` to the ``CodeView`` Library.
-There is some code in the ``CodeView`` reader that was extracted/adapted
-from ``tools/llvm-readobj/COFFDumper.cpp`` that can be moved to the ``CodeView``
+### Move ``initializeFileAndStringTables`` to the CodeView Library.
+There is some code in the CodeView reader that was extracted/adapted
+from ``tools/llvm-readobj/COFFDumper.cpp`` that can be moved to the CodeView
 library.
 
 We had a similar case with code shared with ``llvm-pdbutil`` that was moved
-to the ``PDB`` library: **[D122226](https://reviews.llvm.org/D122226)**
+to the PDB library: **[D122226](https://reviews.llvm.org/D122226)**
 
-### Move ``getSymbolKindName`` and ``formatRegisterId`` to the ``CodeView`` Library.
-There is some code in the ``CodeView`` reader that was extracted/adapted
+### Move ``getSymbolKindName`` and ``formatRegisterId`` to the CodeView Library.
+There is some code in the CodeView reader that was extracted/adapted
 from ``lib/DebugInfo/CodeView/SymbolDumper.cpp`` that can be used.
 
 ### Use of ``std::unordered_set`` instead of ``std::set``.
@@ -129,9 +129,9 @@ common module.
 [D137156](https://reviews.llvm.org/D137156)**
 
 During the traversal of the debug information sections, we created the
-logical lines representing the ``disassembled instructions`` from the ``text
-section`` and the logical lines representing the ``line records`` from the
-``debug line`` section. Using the ranges associated with the logical scopes,
+logical lines representing the **disassembled instructions** from the **text
+section** and the logical lines representing the **line records** from the
+**debug line** section. Using the ranges associated with the logical scopes,
 we will allocate those logical lines to their logical scopes.
 
 Consider the case when any of those lines become orphans, causing
@@ -143,27 +143,27 @@ incorrect scope parent for disassembly or line records.
 Only linked executables are handled. It does not support relocatable
 files compiled with ``-ffunction-sections``.
 
-### Add support for DWARF v5 .debug_names section / CodeView public symbols stream.
+### Add support for DWARF v5 `.debug_names` section / CodeView public symbols stream.
 **[D125783](https://reviews.llvm.org/D125783#inline-1294142)**
 
-The ``DWARF`` and ``CodeView`` readers use the public names information to create
-the instructions (``LVLineAssembler``). Instead of relying on ``DWARF`` section
-names (``.debug_pubnames``, ``.debug_names``) and ``CodeView`` ``public symbol`` stream
+The DWARF and CodeView readers use the public names information to create
+the instructions (``LVLineAssembler``). Instead of relying on DWARF section
+names (``.debug_pubnames``, ``.debug_names``) and CodeView public symbol stream
 (``S_PUB32``), the readers should collect the needed information while processing
 the debug information.
 
 If the object file supports the above section names and stream, use them
 to create the public names.
 
-### Add support for some extra `DWARF` locations.
-The following ``DWARF`` debug location operands are not supported:
+### Add support for some extra DWARF locations.
+The following DWARF debug location operands are not supported:
 
-* DW_OP_const_type
-* DW_OP_entry_value
-* DW_OP_implicit_value
+* `DW_OP_const_type`
+* `DW_OP_entry_value`
+* `DW_OP_implicit_value`
 
 ### Add support for additional binary formats.
-* Extended COFF ``(XCOFF)``
+* Extended COFF (`XCOFF`)
 
 ### Add support for ``JSON`` or ``YAML``
 The logical view uses its own and non-standard free form text when