Ignore pcache directory

http://github.com/sigma/pcache
pcache is used by gist.el
Remove documentation of obsolete prelude-markdown
Merge pull request #548 from bpoweski/patch-1

Remove documentation of obsolete prelude-markdown
Define a few keybindings in terms of help-command
Newline at end of file
Add license badge
Merge pull request #549 from toctan/require-eof

Newline at end of file
Add dockerfile-mode to the prelude-auto-install-alist
Merge pull request #550 from bronislav/add-dockerfile-mode

Add dockerfile-mode to the prelude-auto-install-alist
Merge remote-tracking branch 'upstream/master'

Conflicts:
	.gitignore
Update