Add spellsync plugin to vim

Enables easier vcs integration of vim spelllang dictionaries. Will cause
them to be reloaded on external editing, add their binary parts to
ignore files, and set their addition files to unison merge mode.

nvim/.config/nvim/init.vim

@@ -68,6 +68,7 @@ Plug 'dyng/ctrlsf.vim'
 Plug 'lervag/wiki.vim'
 Plug 'alok/notational-fzf-vim'
 " Prose Workflow
+Plug 'micarmst/vim-spellsync'
 Plug 'kana/vim-textobj-user' " dependency for most other textobj plugins
 Plug 'reedes/vim-textobj-sentence' " extends the capabilities of sentence detection
 " and allows you to jump to the *end* of this <g)> or last <g(> sentence.