Add initial plurals .ts files for i18n examples

Since we automatically create a plurals .ts file with
qt_add_translations, the i18n examples pollute the source tree of Qt
with generated .ts files.

Fix this by adding initial .ts files to the repository.

Pick-to: 6.7 6.8
Fixes: QTBUG-124709
Change-Id: I875c8395a975f7182d0a10781d96a9a78b2c1e4a
Reviewed-by:  Alexey Edelev <[email protected]>

Author: jobor

examples/linguist/arrowpad/arrowpad_en.ts

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+When using CMake, run the update_translations CMake target
+to populate the source strings in this file.
+
+When using QMake, run the following command:
+    lupdate arrowpad.pro
+-->
+<!DOCTYPE TS>
+<TS version="2.1" language="en_US"/>

examples/linguist/hellotr/hellotr_en.ts

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+When using CMake, run the update_translations CMake target
+to populate the source strings in this file.
+
+When using QMake, run the following command:
+    lupdate hellotr.pro
+-->
+<!DOCTYPE TS>
+<TS version="2.1" language="en_US"/>

examples/linguist/trollprint/trollprint_en.ts

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+When using CMake, run the update_translations CMake target
+to populate the source strings in this file.
+
+When using QMake, run the following command:
+    lupdate trollprint.pro
+-->
+<!DOCTYPE TS>
+<TS version="2.1" language="en_US"/>