Modify keyboard bindings

Mod4 (Windows key) is used everywhere.

The arrow keys are h (left), l (down), k (up) and t (right) to remain
consistent with Vim. These bindings are for the Workman keyboard layout.
Change font from DeJavu Sans Mono (10 px) to Terminus (9 px)
Add ctrlp.vim configuration
Remove wildignore

Such verbose wildignore seems to interfere with several plugins,
including tpope/vim-fugitive.

There is no need for it anyway.