Update runtime files

runtime/syntax/gemtext.vim

@@ -0,0 +1,24 @@
+" Vim syntax file
+" Language:             Gemtext markup language
+" Maintainer:           Suneel Freimuth <suneelfreimuth1@gmail.com>
+" Latest Revision:      2020-11-21
+" Filenames:            *.gmi
+
+if exists('b:current_syntax')
+    finish
+endif
+
+syntax match  Heading  /^#\{1,3}.\+$/
+syntax match  List     /^\* /
+syntax match  LinkURL  /^=>\s*\S\+/
+syntax match  Quote    /^>.\+/
+syntax region Preformatted start=/^```/ end=/```/
+
+highlight default link Heading  Special
+highlight default link List     Statement
+highlight default link LinkURL  Underlined
+highlight default link Quote    Constant
+highlight default link Preformatted Identifier
+
+let b:current_syntax = 'gemtext'
+