VIM: adds firevim config

Does 2 thing:
* sets up my setting for editing text (spell checking etc)
* Sets the content type to html for domains starting with mail.

nvim/.config/nvim/plugin/firevim.vim

@@ -0,0 +1,16 @@
+let g:firenvim_config = { 
+    \ 'globalSettings': {
+        \ 'alt': 'all',
+    \  },
+    \ 'localSettings': {
+        \ 'mail.*': {
+            \ 'content': 'html',
+        \ },
+    \ }
+\ }
+
+" If we are in firevim, I probably want my normal text settings
+" That is, spell on and undo points when punctuation is added
+if exists('g:started_by_firenvim')
+	call mine#functions#text()
+endif