There are a few editor-specific configuration files in the crawl repo, which you
may choose to enable. Currently the provided files are:

Vim:
source/dat/vim/syntax/levdes.vim, which includes a header at the top of the file
telling you how to install it. This will be useful if you are editing the .des
files used to define vaults or levels, but is not necessary otherwise.

You can also set the appropriate indentation options for crawl source files
by adding the following to your .vimrc or as a new file in ~/.vim/ftdetect/ :
  autocmd! BufNewFile,BufRead */crawl-ref/* setlocal sw=4 et

Emacs:
source/dat/emacs/dir-locals.el contains a couple of settings for editing C++
source files in the crawl-approved style, and can be activated by copying (or,
preferably, symlinking) it to source/.dir-locals.el