Implement rp CLI: rich-print markdown, JSON, code, and more

- Add typer CLI with auto file-type detection by extension
- Support markdown (rich.Markdown), JSON (rich.JSON), and 30+ code
  languages via Pygments syntax highlighting
- Features: line numbers toggle, pager support, stdin input,
  configurable color themes
- Project metadata: MIT license, author, classifiers, entry point

src/rp/render.py

@@ -0,0 +1,55 @@
+"""Core rendering module for rp."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from rich.console import Console
+from rich.json import JSON as RichJSON
+from rich.markdown import Markdown
+from rich.syntax import Syntax
+
+
+@dataclass
+class RenderOptions:
+    theme: str = "monokai"
+    line_numbers: bool | None = None
+    pager: bool | None = None
+
+
+_MARKDOWN_TYPES = {"markdown", "md"}
+_JSON_TYPES = {"json"}
+
+
+def render(
+    content: str, file_type: str, console: Console, options: RenderOptions
+) -> None:
+    line_numbers = options.line_numbers
+    if line_numbers is None:
+        line_numbers = file_type not in _MARKDOWN_TYPES and file_type not in _JSON_TYPES
+
+    use_pager = options.pager
+    if use_pager is None:
+        import sys
+
+        use_pager = sys.stdout.isatty()
+
+    if file_type in _MARKDOWN_TYPES:
+        renderable = Markdown(content)
+    elif file_type in _JSON_TYPES:
+        try:
+            renderable = RichJSON(content)
+        except Exception:
+            renderable = Syntax(
+                content, "json", theme=options.theme, line_numbers=line_numbers
+            )
+    else:
+        renderable = Syntax(
+            content, file_type, theme=options.theme, line_numbers=line_numbers
+        )
+
+    if use_pager:
+        with console.pager(styles=True):
+            console.print(renderable)
+    else:
+        console.print(renderable)