v1.25.4

Add `reStructuredText` support in templates

This release adds `reStructuredText` code to the `annotate_file_content`
template. (All other templates are markup language agnostic).

To create a new ReStructuredText note invoke Tp-Note with:

```sh
TPNOTE_EXTENSION_DEFAULT=rst tpnote
```

To make ReStructuredText the default markup language for all future new notes,
write a configuration file '`~/.config/tpnote/tpnote.toml`' with the following
content:

```toml
[base_scheme.filename]
extension_default="rst"
```

Other new features:

* Make `exporter_highlighting_css` configurable
* Make `viewer_highlighting_css` configurable

Some minor bug fixes shipped with this release:

* errorpage: display correct path to browsed doc
* Rst renderer: always `trim()` input