Migrate TravisCI to GHA

.github/workflows/snippets_checks.yml

@@ -0,0 +1,43 @@
+# This workflow performs the checks like license check,
+# doxygen, unit tests etc.
+name: Snippets Checks
+
+on:
+  pull_request:
+  workflow_dispatch:
+  push:
+    branches:
+      - development
+
+jobs:
+  Snippets-check:
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/armmbed/mbed-os-env:master-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v2
+
+      - name: clone mbed-os
+        run: git clone https://github.com/armmbed/mbed-os.git
+
+      - name: add mbed_app.json
+        run: |
+          echo  '{ "target_overrides": { "K64F": { "target.features_add": ["BLE"] } } }' > mbed_app.json
+
+      - name: validate code snippets
+        run: ./check_tools/find_bad_code_snippets.sh
+
+      - name: find remaining TODOs
+        run: |
+          TODO_COUNT=0
+          for f in $(find -name mbed-os -prune -o -name '*.md' -print)
+          do
+              for l in $(sed -n '/```.*TODO/I=' $f)
+              do
+                  echo "TODO in $f line $l"
+                  TODO_COUNT=$(expr $TODO_COUNT + 1)
+              done
+          done
+          echo "Total number of TODOs: $TODO_COUNT"

docs/api/connectivity/bluetooth/BLE.md

@@ -47,7 +47,7 @@ the events (methods) you are interested in, the others will inherit the do-nothi
 
 All BLE operations are executed on an instance of BLE accessible through a function in the header `ble/BLE.h`.
 
-```c
+```cpp
 #include "ble/BLE.h"
 
 BLE& mydevicename = BLE::Instance();

docs/api/drivers/driver_interfaces.md

@@ -72,7 +72,7 @@ class LEDAnimator {
     }
 
     LEDAnimator(mbed::interface::DigitalOut *red, mbed::interface::DigitalOut *green, mbed::interface::DigitalOut *blue) : _red(red), _green(green), _blue(blue), _internally_created(false) {
-    ...
+    // do something
     }
 
     ~LEDAnimator() {
@@ -90,7 +90,7 @@ private:
     mbed::interface::DigitalOut *_blue;
 
     bool _internally_created;
-}
+};
 ```
 
 Now it is possible for your existing library to use the external GPIO expander without any knowledge that it is external. As long as your `my_company::I2CExpander::DigitalOut` class implements the `mbed::interface::DigitalOut` interface properly, your code will work as it did before. You can even have some of the GPIO be internal or external if your design calls for it!
@@ -103,7 +103,7 @@ The inheritance of a driver from the new driver interface is conditional upon `F
 
 When `FEATURE_EXPERIMENTAL_API` is disabled, the following type alias is made instead:
 
-```c++
+```
 using mbed::interface::DigitalOut = mbed::DigitalOut;
 ```