Update README.md.

README.md

@@ -97,8 +97,8 @@ It can convert *to*
     not supported in [`gfm`](#markdown-variants).
   - `haddock` ([Haddock
     markup](https://www.haskell.org/haddock/doc/html/ch03s08.html))
-  - `html` or `html5` ([HTML](http://www.w3.org/html/), i.e.
-    [HTML5](http://www.w3.org/TR/html5/)/XHTML [polyglot
+  - `html` or `html5` ([HTML](http://www.w3.org/html/),
+    i.e. [HTML5](http://www.w3.org/TR/html5/)/XHTML [polyglot
     markup](https://www.w3.org/TR/html-polyglot/))
   - `html4` ([XHTML](http://www.w3.org/TR/xhtml1/) 1.0 Transitional)
   - `icml` ([InDesign
@@ -106,7 +106,7 @@ It can convert *to*
   - `jats` ([JATS](https://jats.nlm.nih.gov) XML)
   - `json` (JSON version of native AST)
   - `latex` ([LaTeX](http://latex-project.org))
-  - `man` ([groff
+  - `man` ([roff
     man](http://man7.org/linux/man-pages/man7/groff_man.7.html))
   - `markdown` ([Pandoc’s Markdown](#pandocs-markdown))
   - `markdown_mmd`
@@ -117,7 +117,7 @@ It can convert *to*
     [Markdown](http://daringfireball.net/projects/markdown/))
   - `mediawiki` ([MediaWiki
     markup](https://www.mediawiki.org/wiki/Help:Formatting))
-  - `ms` ([groff
+  - `ms` ([roff
     ms](http://man7.org/linux/man-pages/man7/groff_ms.7.html))
   - `muse` ([Muse](https://amusewiki.org/library/manual)),
   - `native` (native Haskell),