Add fennel support, closes #514

ftplugin/fennel.vim

@@ -0,0 +1,30 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'fennel') == -1
+
+" Vim filetype plugin file
+" Language: FENNEL
+" Maintainer: Calvin Rose
+
+if exists("b:did_ftplugin")
+	finish
+endif
+let b:did_ftplugin = 1
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+"setlocal iskeyword+=!,_,%,?,-,*,!,+,/,=,<,>,.,:,$,^
+setlocal iskeyword=!,$,%,#,*,+,-,.,/,:,<,=,>,?,_,a-z,A-Z,48-57,128-247,124,126,38,94
+
+" There will be false positives, but this is better than missing the whole set
+" of user-defined def* definitions.
+setlocal define=\\v[(/]def(ault)@!\\S*
+
+" Remove 't' from 'formatoptions' to avoid auto-wrapping code.
+setlocal formatoptions-=t
+
+setlocal comments=n:;
+setlocal commentstring=;\ %s
+
+let &cpo = s:cpo_save
+
+endif