Readme updates & switch CI to use main

.github/workflows/test.yml

@@ -2,7 +2,7 @@ name: "Test shellcheck problem matchers"
 on:
   pull_request:
   push:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   lint:

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 ## Testing problem matchers locally
 
-Since GitHub Actions are functionally very similar to [VS Code's problem matchers](https://code.visualstudio.com/Docs/editor/tasks#_defining-a-problem-matcher) (outside of some [exceptions](https://github.com/actions/runner/blob/master/docs/adrs/0276-problem-matchers.md#where-we-diverge-from-vscode)), we can use VS Code locally to quickly test the matcher patterns.
+Since GitHub Actions are functionally very similar to [VS Code's problem matchers](https://code.visualstudio.com/Docs/editor/tasks#_defining-a-problem-matcher) (outside of some [exceptions](https://github.com/actions/runner/blob/main/docs/adrs/0276-problem-matchers.md#where-we-diverge-from-vscode)), we can use VS Code locally to quickly test the matcher patterns.
 
 1. Make sure VS Code `.vscode/tasks.json` file is in sync with actual problem matchers
     ```bash

README.md

@@ -13,7 +13,7 @@ This currently supports the `gcc` and `tty` formats.
 To enable the shellcheck problem matchers, simply add this Action as a step **before** running the actual `shellcheck` command:
 
 ```yaml
-uses: lumaxis/shellcheck-problem-matchers@v1
+uses: lumaxis/shellcheck-problem-matchers@v2
 run: shellcheck -f gcc *.sh
 ```
 
@@ -26,7 +26,7 @@ See the [actions tab](https://github.com/lumaxis/shellcheck-problem-matchers/act
 By default, this Action installs all available problem matchers but you can specify one of the available formats explicitly:
 
 ```yaml
-uses: lumaxis/shellcheck-problem-matchers@v1
+uses: lumaxis/shellcheck-problem-matchers@v2
 with:
   format: gcc # Available options are "gcc" or "tty"
 ```