doc: set edit_uri path for mkdocs
doc: set edit_uri path for mkdocs

Per https://github.com/mkdocs/mkdocs/blob/master/docs/user-guide/configuration.md#edit_uri,
we can set the `edit_uri` configuration parameter to correctly link the
"edit on GitHub" text.

open-craft/opencraft,open-craft/opencraft,open-craft/opencraft,open-craft/opencraft,open-craft/opencraft