This changes preprocessors so that:
- Relative paths in the `command` value are relative to the book root.
- The process current directory is the book root.
This makes it so that it isn't dependent on the directory where `mdbook`
is executed.
Fixes https://github.com/rust-lang/mdBook/issues/1424
This removes the deprecated support for renderer paths that are relative
to the destination. Relative renderer command paths now must always be
relative to the book root.
This removes toml as a public dependency. This reduces the exposure of
the public API, reduces exposure of internal implementation, and makes
it easier to make semver-incompatible changes to toml.
This is accomplished through a variety of changes:
- `get` and `get_mut` are removed.
- `get_deserialized_opt` is renamed to `get`.
- Dropped the AsRef for `get_deserialized_opt` for ergonomics, since
using an `&` for a String is not too much to ask, and the other
generic arg needs to be specified in a fair number of situations.
- Removed deprecated `get_deserialized`.
- Dropped `TomlExt` from the public API.
- Removed `get_renderer` and `get_preprocessor` since they were trivial
wrappers over `get`.
