Update branch of c-sdk repo to main (#223)

Also add missing apostrophe to stdint.readme

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
       - name: Checkout Parent Repo
         uses: actions/checkout@v2
         with:
-          ref: master
+          ref: main
           repository: aws/aws-iot-device-sdk-embedded-C
           path: main
       - name: Clone This Repo

.github/workflows/header-checks.yml

@@ -1,6 +1,6 @@
 name: FreeRTOS-Header-Checker
 
-on: [pull_request]          
+on: [pull_request]
 
 jobs:
   header-checker:
@@ -12,15 +12,15 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: 3.8.5
-          architecture:   x64  
-        env:  
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} 
-      
+          architecture:   x64
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
       # Get latest checks from master
       - name: Checkout FreeRTOS Tools
         uses: actions/checkout@v2
         with:
-          repository: FreeRTOS/FreeRTOS 
+          repository: FreeRTOS/FreeRTOS
           ref:  master
           path: tools
 
@@ -29,18 +29,18 @@ jobs:
         uses: actions/checkout@v2
         with:
           ref:  ${{ github.event.pull_request.head.sha }}
-          path: inspect  
-          
+          path: inspect
+
       # Collect all affected files
       - name: Collecting changed files
         uses: lots0logs/gh-action-get-changed-files@2.1.4
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
-      
-      # Run checks     
+
+      # Run checks
       - name: Check File Headers
         run: |
           cd inspect
           ../tools/.github/scripts/check-header.py --kernel --json ${HOME}/files.json
           exit $?
-                  
+