Ensure inline code is markdown-escaped as such, HTML tags are removed from summaries, and that code snippets in descriptions are properly indented.

Affects DocBlocks for the following core elements in wp-includes/formatting.php:
* Markdown-indent code snippets in the description for `wptexturize()`
* Backtick-escape inline code in a parameter description for `_wptexturize_pushpop_element()`
* Backtick-escape inline code in the description for `shortcode_unautop()`
* Backtick-escape HTML tags in the description for `convert_chars()`
* Markdown-indent a code snippet in the description for `_split_str_by_whitespace()`
* Backtick-escape an `<img>` tag in the description for `translate_smiley()`
* Add markdown formatting to the description for `links_add_target()`
* Backtick-escape HTML tags in the description for `wp_strip_all_tags()`

Props rarst.
See #30473.

Built from https://develop.svn.wordpress.org/trunk@30540


git-svn-id: http://core.svn.wordpress.org/trunk@30529 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Ensure inline code is markdown-escaped as such, HTML tags are removed from summaries, and that code snippets in descriptions are properly indented.

Affects DocBlocks for the following core elements:
* Markdown-indent a code snippet in the description for `_deprecated_argument()`
* Markdown-indent a code snippet in the description for `wp_localize_script()`
* Backtick-escape HTML tags in two parameter descriptions for `wp_register()`
* Various DocBlock formatting in the description for `get_bloginfo()`
* Remove HTML tag from the summary for `_wp_render_title_tag()`
* Backtick-escape a HTML tag in the description for `get_archives_link()`
* Markdown-indent a code snippet in the description for `wp_admin_css_color()`
* Markdown-indent a code snippet in the description for the `welcome_panel` hook

Props rarst.
See #30473.

Built from https://develop.svn.wordpress.org/trunk@30541


git-svn-id: http://core.svn.wordpress.org/trunk@30530 1a063a9b-81f0-0310-95a4-ce76da25c4cd