elisp: Ignore more build tools

.eask, .eldev, .keg are other build tools like .cask.
dist is the default folder to build package distribution files.

Elisp.gitignore

@@ -2,7 +2,13 @@
 *.elc
 
 # Packaging
-.cask
+.cask/
+.eask/
+.eldev/
+.keg/
+
+# Built distribution
+dist/
 
 # Backup files
 *~