Use hybrid GitHub/common markdown for code blocks

 
 ## Usage
 
-```bash
-mkdir example.site && cd example.site
-poetry init --name=example-site
-poetry add webint
-poetry run web scaffold 
-poetry version minor
-poetry publish
-
-web config --host digitalocean --token {YOUR_TOKEN}
-web init example.site example-site example:app
-```
+    bash
+    mkdir example.site && cd example.site
+    poetry init --name=example-site
+    poetry add webint
+    poetry run web scaffold
+    poetry version minor
+    poetry publish
+
+    web config --host digitalocean --token {YOUR_TOKEN}
+    web init example.site example-site example:app
 
 ### Hack
 
-```bash
-poetry run web run example:app --port 9999
-```
+    !bash
+    poetry run web run example:app --port 9999
 
 Changes to your python code will auto-reload the local development server.
 
 #### Deploy an update
 
-```bash
-poetry version (major|minor|patch)
-poetry publish
-```
+    !bash
+    poetry version (major|minor|patch)
+    poetry publish
 
 Wait a couple minutes and update your site at https://example.site/system/software

 
     """
 
-    pattern = r"^`{3}.*"
+    pattern = r"^[ ]{4}"
 
     def parse(self, block):
         """"""
-        text = block.removeprefix("```").removesuffix("```")
-        if text.startswith("\n"):
-            html = E.PRE(text.strip())
-        elif text.startswith(">>> "):
+        text = dedent(block)
+        if text.startswith(">>> "):
             lexer = pygments.lexers.PythonConsoleLexer()
             lexer.add_filter("codetagify")
             formatter = pygments.formatters.HtmlFormatter(cssclass="doctest")
             code = pygments.highlight(text, lexer, formatter)
             html = lxml.html.fromstring(code)
-        else:
-            language, _, code = text.partition("\n")
+        elif text.startswith("!"):
+            language, _, code = text.lstrip("!").partition("\n")
             lexer = pygments.lexers.get_lexer_by_name(language)
             lexer.add_filter("codetagify")
             formatter = pygments.formatters.HtmlFormatter()
             code = pygments.highlight(text, lexer, formatter)
             html = lxml.html.fromstring(code)
+        else:
+            html = E.PRE(text.strip())
         return html