Fixes typo
Adds additional read me clarifications

- Adds link to wiki, where instructions for difference system
configurations can be built out.
- Adds additional info about where cloning the repo will place download
it to.
Adds disclaimer

Bundler can take 10 minutes or longer to complete, this should be noted
in the readme. This adds a disclaimer.
Adds additional info to readme

Adds additional info about third party tools mentioned in the read me.
Fixes typo

Ampersand was used in place of question mark for the beginning of a
search query string, this commit fixes that typo.
Fixes link typo

Updates wiki link
Updates readme

Updates links in reedme
Merge pull request #130 from codeforamerica/readme-updates

Readme updates