inelegant error handeling for export yml errors re #773
Tweaks to docnav, display in top section as well.
Merge pull request #782 from mapbox/docnav

[website] Tweaks to docnav
grammar
fill out context
exporting style should link to /styles, not /data
Revert "exporting style should link to /styles, not /data"

This reverts commit 241cbec3933f1d356ae404b8063330957621ca00.
clarify saving custom source in order to be usable
Revert "clarify saving custom source in order to be usable"

This reverts commit 08ab924c9023a62af4d2744974cb66d3d3ad59d0.
clarify source preview
add comments
better wording
encourage 'Save as' for first-time sources
Merge branch 'mb-pages' into upload-yml-error
proper capitalization
fix bad/missing font
add error modal
Merge pull request #791 from mapbox/jm-fixes

various fixes from running through the quickstarts
Merge pull request #786 from mapbox/upload-yml-error

Stopgap for yaml error on upload, fixes #773
update changelog