Update lfe_shell
Update lfe_shell

- Add (h) as an alias for (help)
- Update the output of help/0
  - Alphabetize
  - Add missing functions, namely doc/1
  - Normalize language to use imperative tense
  - Correct a typo in clear/0 description: s/the the/the/

rvirding/lfe,jjhoo/lfe,lfe/lfe,jjhoo/lfe,rvirding/lfe,lfe/lfe