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/corpus/describe_blocks.txt

@@ -0,0 +1,143 @@
+================================================================================
+Basic Describe block
+================================================================================
+
+Describe "basic functionality"
+  echo "test"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (string
+      (string_content))
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))))
+
+================================================================================
+Focused Describe block
+================================================================================
+
+fDescribe "focused test"
+  echo "focused"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (string
+      (string_content))
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))))
+
+================================================================================
+Skipped Describe block
+================================================================================
+
+xDescribe "skipped test"
+  echo "skipped"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (string
+      (string_content))
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))))
+
+================================================================================
+Describe with raw string
+================================================================================
+
+Describe 'raw string test'
+  echo "test"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (raw_string)
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))))
+
+================================================================================
+Describe with word description
+================================================================================
+
+Describe simple_test
+  echo "test"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (word)
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))))
+
+================================================================================
+Empty Describe block
+================================================================================
+
+Describe "empty test"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (string
+      (string_content))))
+
+================================================================================
+Describe with multiple statements
+================================================================================
+
+Describe "multiple statements"
+  echo "first"
+  echo "second"
+  local var="value"
+End
+
+--------------------------------------------------------------------------------
+
+(program
+  (shellspec_describe_block
+    description: (string
+      (string_content))
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))
+    (command
+      name: (command_name
+        (word))
+      argument: (string
+        (string_content)))
+    (declaration_command
+      (variable_assignment
+        name: (variable_name)
+        value: (string
+          (string_content))))))