Vesta

Added
- All clients now support a user-provided [httpx.Client](https://www.python-httpx.org/api/#client).
- Added support for the VBML `absolutePosition` style.
- Added support for the VBML `rawCharacters` component field.
- `SubscriptionClient` provides a client interface to Vestaboard's Subscription API.

Changed
- The `encode_*()` functions now consistently specify keyword-only arguments.
- Vestaboard has deprecated the Platform API, so our `Client` interface is also
considered deprecated. Switch to `SubscriptionClient`, which offers nearly
identical functionality.

Added
- `VBMLClient` provides a client interface to Vestaboard's [VBML (Vestaboard
Markup Language)](https://docs.vestaboard.com/docs/vbml) API.
- Added support for Python 3.12.

Changed
- Switched to a `pyproject.toml`-based package configuration.

Added
- Added text message support to `ReadWriteClient.write_message()`.

Fixed
- `ReadWriteClient.get_message()` now correctly returns a `Rows` value rather
than a JSON-encoded string.

Added
- Added `max_rows` to `encode_text()` for controlling the maximum number of rows
that will be returned (defaulting to 6). It can be set to a lower value to
produce a partial board or 0 to support unlimited rows.

Changed
- `encode_text()` no longer raises `ValueError` when the result exceeds the
maximum number of rows. Instead, the result is truncated to `max_rows`.

Added
- Added `Color.BLANK` and `Color.FILLED` color values.

Changed
- Switched to [HTTPX](https://www.python-httpx.org/) as the underlying HTTP library.
- `Color.BLACK` now uses the official "black" character code (70). Use `Color.BLANK`
for character code 0 (previously used by `Color.BLACK`).
- The default "fill" color is now `Color.BLANK` instead of `Color.BLACK`.

Removed
- Dropped support for Python 3.7.

Added
- `LocalClient` provides a client interface to Vestaboard's Local API.
- `ReadWriteClient` provides a client interface to Vestaboard's Read / Write API.

Changed
- The documentation now uses the [Furo theme](https://github.com/pradyunsg/furo).
- [Requests](https://requests.readthedocs.io/) version 2.27.0 or later is now required.