Refactor Extension API docs (#946)

* Move Patterns sections.  Fixes #729.
* Rewrite tree processor docs. Fixes #949.

Author: merriam

.spell-dict

@@ -30,6 +30,7 @@ deregister
 Dmitry
 docdata
 ElementTree
+encodings
 extendMarkdown
 Fauske
 Formatter
@@ -58,6 +59,7 @@ Manfed
 markdownFromFile
 Maruku
 md
+metadata
 MkDocs
 multi
 MultiMarkdown

docs/change_log/index.md

@@ -5,6 +5,7 @@ Python-Markdown Change Log
 
 Under development: version 3.2.2 (a bug-fix release).
 
+* Refactor extension API documentation (#729).
 * Load entry_points (for extensions) only once using `importlib.metadata`.
 * Do not double escape entities in TOC.
 * Correctly report if an extension raises a `TypeError` (#939).

docs/change_log/release-3.2.md

@@ -93,4 +93,4 @@ The following bug fixes are included in the 3.2 release:
 * HTML tag placeholders are no longer included in  `.toc_tokens` (#899).
 * Unescape backslash-escaped characters in TOC ids (#864).
 * Refactor bold and italic logic in order to solve complex nesting issues (#792).
-* Always wrap CodeHilite code in `code` tags (#862)
+* Always wrap CodeHilite code in `code` tags (#862).