Add GitHub action for labelling PRs

.github/labeler.yml

@@ -0,0 +1,64 @@
+go:
+  - changed-files:
+      - any-glob-to-any-file:
+          - src/**
+          - main.go
+          - go.mod
+          - go.sum
+
+shell:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**
+
+bash:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**/*.bash
+
+zsh:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**/*.zsh
+
+fish:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**/*.fish
+
+vim:
+  - changed-files:
+      - any-glob-to-any-file:
+          - plugin/**
+
+docs:
+  - changed-files:
+      - any-glob-to-any-file:
+          - '*.md'
+          - doc/**
+          - man/**
+
+ci:
+  - changed-files:
+      - any-glob-to-any-file:
+          - .github/**
+
+build:
+  - changed-files:
+      - any-glob-to-any-file:
+          - Makefile
+          - .goreleaser.yml
+          - Dockerfile
+
+test:
+  - changed-files:
+      - any-glob-to-any-file:
+          - test/**
+          - src/**/*_test.go
+
+install:
+  - changed-files:
+      - any-glob-to-any-file:
+          - install
+          - install.ps1
+          - uninstall