This removes mdBook in favor of a flat docs folder generating a single
`README.md` in the repository root.
Installation and usage instructions have also been expanded slightly.
It's possible to end up with "recursive embeds" when two notes embed
each other. This happens for example when a `Note A.md` contains
`![[Note B]]` but `Note B.md` also contains `![[Note A]]`.
By default, this will trigger an error and display the chain of notes
which caused the recursion.
Using the new `--no-recursive-embeds`, if a note is encountered for a
second time while processing the original note, rather than embedding it
again a link to the note is inserted instead to break the cycle.
See also: https://github.com/zoni/obsidian-export/issues/1
By default hidden files, patterns listed in `.export-ignore` as well as
any files ignored by git are excluded from exports. This behavior has
been made configurable on the CLI using the new flags `--hidden`,
`--ignore-file` and `--no-git`.
