Merge pull request github#350 from github/tidy-up-the-readme

Tidy up the readme

Author: gjtorikian

README.md

@@ -37,32 +37,36 @@ Or, more realistically:
     require 'github/markup'
     GitHub::Markup.render(file, File.read(file))
 
+Contributing
+------------
+
+See [Contributing](CONTRIBUTING.md)
+
 HTML sanitization
 -----------------
 
 HTML rendered by the various markup language processors gets passed through an [HTML sanitization filter](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/sanitization_filter.rb) for security reasons. HTML elements not in the whitelist are removed. HTML attributes not in the whitelist are removed from the preserved elements.
 
 The following HTML elements, organized by category, are whitelisted:
 
-* Headings: h1, h2, h3, h4, h5, h6, h7, h8
-* Prose: p, div, blockquote
-* Preformatted: pre
-* Inline: b, i, strong, em, tt, code, ins, del, sup, sub, kbd, samp, q, var
-* Lists: ol, ul, li, dl, dt, dd
-* Tables: table, thead, tbody, tfoot, tr, td, th
-* Breaks: br, hr
-* Ruby (East Asian): ruby, rt, rp
+|Type | Elements
+|------|----------
+|Headings | `h1`, `h2`, `h3`, `h4`, `h5`, `h6`, `h7`, `h8`
+|Prose |  `p`, `div`, `blockquote`
+|Formatted | `pre`
+| Inline | `b`, `i`, `strong`, `em`, `tt`, `code`, `ins`, `del`, `sup`, `sub`, `kbd`, `samp`, `q`, `var`
+| Lists | `ol`, `ul`, `li`, `dl`, `dt`, `dd`
+| Tables | `table`, `thead`, `tbody`, `tfoot`, `tr`, `td`, `th`
+| Breaks | `br`, `hr
+| Ruby (East Asian) | `ruby`, `rt`, `rp`
 
 The following attributes, organized by element, are whitelisted:
 
-* a: href (http://, https://, mailto://, github-windows:// and github-mac:// URI schemes and relative paths only)
-* img: src (http:// and https:// URI schemes and relative paths only)
-* div: itemscope, itemtype
-* all: abbr, accept, accept-charset, accesskey, action, align, alt, axis, border, cellpadding, cellspacing, char, charoff, charset, checked, cite, clear, cols, colspan, color, compact, coords, datetime, dir, disabled, enctype, for, frame, headers, height, hreflang, hspace, ismap, label, lang, longdesc, maxlength, media, method, multiple, name, nohref, noshade, nowrap, prompt, readonly, rel, rev, rows, rowspan, rules, scope, selected, shape, size, span, start, summary, tabindex, target, title, type, usemap, valign, value, vspace, width, itemprop
+|Element | Attributes
+|------|----------
+| `a` | `href` (`http://`, `https://`, `mailto://`, `github-windows://`, and `github-mac://` URI schemes and relative paths only)
+| `img` | `src` (`http://` and `https://` URI schemes and relative paths only)
+| `div` | `itemscope`, `itemtype`
+| All | `abbr`, `accept`, `accept-charset`, `accesskey`, `action`, `align`, `alt`, `axis`, `border`, `cellpadding`, `cellspacing`, `char`, `charoff`, `charset`, `checked`, `cite`, `clear`, `cols`, `colspan`, `color`, `compact`, `coords`, `datetime`, `dir`, `disabled`, `enctype`, `for`, `frame`, `headers`, `height`, `hreflang`, `hspace`, `ismap`, `label`, `lang`, `longdesc`, `maxlength`, `media`, `method`, `multiple`, `name`, `nohref`, `noshade`, `nowrap`, `prompt`, `readonly`, `rel`, `rev`, `rows`, `rowspan`, `rules`, `scope`, `selected`, `shape`, `size`, `span`, `start`, `summary`, `tabindex`, `target`, `title`, `type`, `usemap`, `valign`, `value`, `vspace`, `width`, `itemprop`
 
-Note that the id attribute is *not* whitelisted.
-
-Contributing
-------------
-
-See [Contributing](CONTRIBUTING.md)
+Note that the `id` attribute is *not* whitelisted.