nvim: Remove pencil to fix relative cursor movement

Cursor movement works better for soft-wrapped prose files now:
When just using j/k to move vertically, the cursor will jump between the
different parts of a single wrapped line. That means you can easily move
anywhere you want on your lines, exactly as it's shown to you.

If, however, prefixing your j/k move with a number to move a relative
number of lines, it will no longer take wrapping into account. That
means you can not jump instantly to *any* part of a wrapped lines,
however on the other hand the relative line numbers on the side never
lie now: You will jump exactly as many lines as are shown on the side.
This is a tradeoff I am happily willing to make.

Additionally had to remove vim-pencil to get the movement to work, but
since it did not provide any visible pros anymore, this should not be a
big issue.

nvim/.config/nvim/after/plugin/prose.vim

@@ -1,9 +1,7 @@
 " PROSE: function to automatically enables markdown plugins for md & txt files
 function! s:Prose()
-  call plug#load('vim-pencil')
   call plug#load('goyo.vim')
   call plug#load('limelight.vim')
-  call pencil#init()
   " PLUGIN: vim-textobj-sentence
   " enable extended sentence textobject use on md and plaintext files
   call textobj#sentence#init()