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/06.scope_spec.sh

@@ -0,0 +1,49 @@
+#shellcheck shell=sh
+
+# Each block (example group / example) runs within subshell.
+# It mean that it works like lexical scope.
+
+Describe 'scope example'
+  foo() { echo "foo"; } # It can call from anywhere within this example group
+
+  # By the way, you can only use shellspec DSL or define function here.
+  # Of course it is possible to write freely within the defined function
+  # but other code may breaks isolation of tests.
+
+  It 'calls "foo"'
+    When call foo
+    The output should eq 'foo'
+  End
+
+  It 'defines "bar" function'
+    bar() { echo "bar"; }
+    When call bar
+    The output should eq 'bar'
+  End
+
+  It 'can not call "bar" function, because different scope'
+    When call bar
+    The status should be failure # probably status is 127
+    The stderr should be present # probably stderr is "bar: not found"
+  End
+
+  It 'redefines "foo" function'
+    foo() { echo "FOO"; }
+    When call foo
+    The output should eq 'FOO'
+  End
+
+  It 'calls "foo" function of outer scope (not previous example)'
+    When call foo
+    The output should eq 'foo'
+  End
+
+  Describe 'sub block'
+    foo() { echo "Foo"; }
+
+    It 'calls "foo" function of upper scope'
+      When call foo
+      The output should eq 'Foo'
+    End
+  End
+End