feat: implement complete tree-sitter-shellspec grammar with comprehensive testing

- Add full ShellSpec grammar extending tree-sitter-bash
- Support all ShellSpec constructs: Describe, Context, It, hooks, utilities
- Include Data block parsing with statements and argument styles
- Add 61 comprehensive test cases covering real-world patterns
- Implement optimized GitHub workflows with CI/CD automation
- Configure complete development tooling (linting, formatting, pre-commit)
- Add comprehensive documentation and contribution guidelines
- Optimize grammar conflicts to zero warnings
- Support editor integration for Neovim, VS Code, Emacs

Breaking Changes:
- Initial release, no previous API to break

BREAKING CHANGE: Initial implementation of tree-sitter-shellspec grammar

# Conflicts:
#	.github/workflows/codeql.yml
#	.github/workflows/pr-lint.yml
#	.pre-commit-config.yaml

# Conflicts:
#	.github/workflows/pr-lint.yml

# Conflicts:
#	.github/workflows/pr-lint.yml

test/spec/10.modifier_spec.sh

@@ -0,0 +1,76 @@
+#shellcheck shell=sh
+
+Describe 'modifier example'
+  data() {
+    echo '1 a A'
+    echo '2 b B'
+    echo '3 c C'
+    echo '4 d D'
+  }
+
+  Describe 'line modifier'
+    It 'gets specified line'
+      When call data
+      The line 2 of stdout should eq "2 b B"
+      The stdout line 2 should eq "2 b B" # you can also write like this
+    End
+  End
+
+  Describe 'lines modifier'
+    It 'counts lines'
+      When call data
+      The lines of stdout should eq 4
+    End
+  End
+
+  Describe 'word modifier'
+    It 'gets specified word'
+      When call data
+      The word 5 of stdout should eq "b"
+    End
+  End
+
+  Describe 'length modifier'
+    It 'counts length'
+      When call data
+      The length of stdout should eq 23 # 6 * 4 - 1
+      # Each lines length is 6 including newline,
+      # but trailing newlines are removed.
+    End
+  End
+
+  Describe 'contents modifier'
+    It 'counts length'
+      The contents of file "data.txt" should eq "data"
+    End
+  End
+
+  Describe 'result modifier'
+    echo_ok() { echo ok; }
+    It 'calls function'
+      The result of function echo_ok should eq "ok"
+    End
+  End
+
+  Describe 'modifier'
+    It 'can use ordinal number (0 - 20)'
+      When call data
+      The second line of stdout should eq "2 b B"
+    End
+
+    It 'can use abbreviation of ordinal number'
+      When call data
+      The 2nd line of stdout should eq "2 b B"
+    End
+
+    It 'is chainable'
+      When call data
+      The word 2 of line 2 of stdout should eq "b"
+    End
+
+    It 'can use language chain'
+      When call data
+      The word 2 of the line 2 of the stdout should eq "b"
+    End
+  End
+End