feat(emacs/README.md): add README.md

src/emacs/README.md

@@ -0,0 +1,31 @@
+lean-mode
+=========
+
+Requirement
+-----------
+
+ - [Emacs 24][emacs24]
+ - [flycheck][flycheck]
+ - [fill-column-indicator][fci]
+
+[emacs24]: http://www.gnu.org/software/emacs/
+[flycheck]: http://flycheck.readthedocs.org/en/latest/
+[fci]: https://github.com/alpaker/Fill-Column-Indicator
+
+Setup
+-----
+
+```elisp
+(setq lean-rootdir "~/projects/lean")
+(setq-local lean-emacs-path
+            (concat (file-name-as-directory lean-rootdir)
+                    (file-name-as-directory "src")
+                    "emacs"))
+(add-to-list 'load-path (expand-file-name lean-emacs-path))
+(require 'lean-mode)
+
+;; customization
+(customize-set-variable 'lean-show-rule-column-method 'vline)
+(customize-set-variable 'lean-rule-column 100)
+(customize-set-variable 'lean-delete-trailing-whitespace t)
+```