updated installation instructions
updated link for api-key in usage section
updated download badge to show total downloads
moved creating a PDF under the supported image type section
changed section title to testing for testing section
updated order of API Reference to match lob.com
added table of contents for api reference
added table of contents for readme
consolidated addresses.created examples
corrected spelling of addresses
updated jobs.create file example to match others
Merge pull request #59 from bsiddiqui/update-documentation

Update documentation