Link to build rules documentation

docs/tools/CLI/cli-compile.md

@@ -39,7 +39,7 @@ The arguments for *compile* are:
 - `-m <MCU>` selects a target. If `detect` or `auto` parameter is passed to `-m`, then Mbed CLI detects the connected target.
 - `-t <TOOLCHAIN>` selects a toolchain defined in `mbed_settings.py`. The value can be `ARM` (Arm Compiler), `GCC_ARM` (GNU Arm Embedded) or `IAR` (IAR Embedded Workbench for Arm).
    <span class="notes">**Note**: `mbed compile -t ARM` selects the Arm Compiler major version based on the Arm architecture version of your target. Arm architecture versions 6 and 7 use Arm Compiler 5, and Arm architecture version 8 uses Arm Compiler 6.</span>
-- `--source <SOURCE>` selects the source directory. The default is `.` (the current directory). You can specify multiple source locations, even outside the program tree.
+- `--source <SOURCE>` selects the source directory. The default is `.` (the current directory). You can specify multiple source locations, even outside the program tree. Find more details about the `--source` switch in the [build rules documentation](/docs/development/tools/build_rules.html).
 - `--build <BUILD>` selects the build directory. Default: `BUILD/` inside your program root.
    <span class="notes">**Note**: `mbed compile` ignores the current build directory; creating multiple build directories leads to errors.</span>
 - `--profile <PATH_TO_BUILD_PROFILE>` selects a path to a build profile configuration file. Example: `mbed-os/tools/profiles/debug.json`.

docs/tools/CLI/cli-create.md

@@ -106,6 +106,8 @@ $ mbed compile -t ARM -m LPC1768 --source project1 --source mbed-os --build BUIL
 $ mbed compile -t ARM -m K64F --source project2 --source mbed-os --build BUILD/project2  
 ```
 
+Find more details on the `--source` switch in the [build rules documentation](/docs/development/tools/build_rules.html).
+
 ### Updating to an upstream version
 
 #### Updating a program

docs/tools/CLI/cli-test-debug.md

@@ -15,7 +15,7 @@ The arguments to `test` are:
 - `--compile`: to only compile the tests.
 - `--run`: to only run the tests.
 - `-n <TESTS_BY_NAME>`: to limit the tests built or run to a comma separated list, for example, `test1, test2, test3`.
-- `--source <SOURCE>`: to select the source directory. The default is `.` for the the current directory. You can specify multiple source locations, even outside the program tree.
+- `--source <SOURCE>`: to select the source directory. The default is `.` for the the current directory. You can specify multiple source locations, even outside the program tree. Find more details about the `--source` switch in the [build rules documentation](/docs/development/tools/build_rules.html).
 - `--build <BUILD>`: to select the build directory. The default is `BUILD/` inside your program.
 - `--profile <PATH_TO_BUILD_PROFILE>`: to select a path to a build profile configuration file, for example, `mbed-os/tools/profiles/debug.json`.
 - `-c or --clean`: to clean the build directory before compiling.

docs/tools/mbed_targets.md

@@ -1,6 +1,6 @@
 ## Adding and configuring targets
 
-Arm Mbed uses JSON as a description language for its build targets. You can find the JSON description of Mbed targets in `targets/targets.json` and in `custom_targets.json` in the root of a project directory. If you provide a source directory using the `--source` switch, Mbed looks for `custom_targets.json` in that directory instead. When you add new targets with `custom_targets.json`, they are added to the list of available targets.
+Arm Mbed uses JSON as a description language for its build targets. You can find the JSON description of Mbed targets in `targets/targets.json` and in `custom_targets.json` in the root of a project directory. If you provide a source directory using the `--source` switch, Mbed looks for `custom_targets.json` in that directory instead. When you add new targets with `custom_targets.json`, they are added to the list of available targets, in addition to the [scanning rules](/docs/development/tools/build_rules.html).
 
 <span class="notes">**Note:** The Online Compiler does not support this functionality. You need to use [Mbed CLI](developing-mbed-cli.html) to take your code offline.</span>