Improve documentation for making changes to a deployed Ghost blog

This line in the README doesn’t actually work:

To make changes to your Ghost blog (like adding a theme to the /content directory, for instance), clone your blog locally using the Heroku Toolbelt:

 heroku git:clone --app YOURAPPNAME

See #62 and #67 for context. From Heroku support:

Recent changes are such that heroku git:clone is only useful for applications that are deployed with Heroku’s hosted git service. In effect this means that applications deployed via GitHub, DropBox or “Deploy to Heroku” buttons will result in an empty repo when cloned.

In that case, you’ll need to download the source repository and add the heroku remote to that repo. Once you’ve done that you can push with git (git push heroku master) and you’ll be able to clone the repo after that.

Pretty bad/inconsistent user experience, but out of our control. We should update the docs to explain a working approach.

[cobyism]

Thanks for the link, @Dreyfuzz. Their instructions there basically seem to boil down to “Add the original repo as a remote and pull from that”, which isn’t really a good solution since pulling from the GitHub remote might pull down an updated version of the codebase rather than what was deployed to Heroku. It’s really frustrating that platform deploys (i.e. using the deploy button) cause this to be a problem. 😞

[mars]

Added docs for ghost-on-heroku upgrades & migrations.