cleanup: improvements to the composite action + document it.

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>

.github/workflows/ci.yml

@@ -15,9 +15,8 @@ jobs:
     name: build syscalls-bumper
     runs-on: ubuntu-latest
     steps:
-
       - name: Checkout libs ⤵️
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: falcosecurity/libs
           path: ${{ github.workspace }}/libs

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-        
+
       - name: Checkout
         uses: actions/checkout@v4
         with:

README.md

@@ -24,3 +24,18 @@ syscalls-bumper -h
     -verbose
       enable verbose logging
 ```
+
+## CI Usage
+
+To better suit the CI usage, a [Github composite action](https://docs.github.com/en/actions/creating-actions/creating-a-composite-action) has been developed.  
+Therefore, running syscalls-bumper in your Github workflow is as easy as adding this step:
+```
+- name: Bump syscalls
+  uses: falcosecurity/syscalls-bumper@main
+  with:
+    # Path to the libs repo.
+    # No default. Mandatory.
+    repo-root: 'true'
+```
+
+> __NOTE:__ Since we don't use annotated tags, one cannot use eg: falcosecurity/syscalls-bumper@v0, but only either exact tag name, branch name or commit hash.

action.yml

@@ -9,21 +9,19 @@ inputs:
 runs:
   using: "composite"
   steps:
-    - uses: robinraju/release-downloader@v1.8
+    - name: Setup Go
+      uses: actions/setup-go@v4
       with:
-        fileName:  syscalls-bumper_*_linux_amd64.tar.gz
-        tarBall: false
-        zipBall: false
-        extract: true
-        latest: true
-        repository: "falcosecurity/syscalls-bumper"
-
-    - name: Bump syscalls
+        go-version-file: "${{ github.action_path }}/go.mod"
+
+    - name: Build tool
       shell: bash
+      working-directory: ${{ github.action_path }}
       run: |
-        ./syscalls-bumper --repo-root ${{ inputs.repo-root }} --overwrite
-    
-    - name: Cleanup
+        make build
+
+    - name: Bump syscalls
       shell: bash
+      working-directory: ${{ github.action_path }}
       run: |
-        rm -rf syscalls-bumper*
+        ./build/syscalls-bumper --repo-root ${{ inputs.repo-root }} --overwrite