Ship the Python README as the PyPI description

The `vtracer` package never declared a `readme`, so its PyPI page rendered
an empty description. Point `[project].readme` at the crate's README, and
mirror it in Cargo.toml alongside the core crate's convention.

Pin the documented install to 1.0.0a2 while the 1.0 line is pre-release:
`--pre` would resolve it, but a bare `pip install vtracer` still lands on
0.6.15, whose cp314 wheels segfault on any keyword argument (pyo3 0.19
predates CPython 3.14 moving `PyTupleObject::ob_item`, #124).

README.md

@@ -206,7 +206,7 @@ See [docs.rs/vtracer](https://docs.rs/vtracer/1.0.0-alpha.2/vtracer/) for the fu
 [`vtracer`](https://pypi.org/project/vtracer/) is also packaged as a Python native extension.
 
 ```sh
-pip install --pre vtracer
+pip install vtracer==1.0.0a2
 ```
 
 ```python

crates/vtracer-py/Cargo.toml

@@ -5,6 +5,7 @@ version = "1.0.0-alpha.2"
 authors = ["Chris Tsang <tyt2y7@gmail.com>"]
 edition = "2024"
 license = "MIT OR Apache-2.0"
+readme = "README.md"
 homepage = "http://www.visioncortex.org/vtracer"
 repository = "https://github.com/visioncortex/vtracer/"
 

crates/vtracer-py/README.md

@@ -8,7 +8,7 @@ this crate adds image decoding and a Pythonic API.
 ## Install
 
 ```sh
-pip install vtracer
+pip install vtracer==1.0.0a2
 ```
 
 ## Usage

crates/vtracer-py/pyproject.toml

@@ -5,6 +5,7 @@ build-backend = "maturin"
 [project]
 name = "vtracer"
 description = "Raster to vector graphics converter — Python bindings for the vtracer framework."
+readme = "README.md"
 requires-python = ">=3.8"
 license = { text = "MIT OR Apache-2.0" }
 authors = [{ name = "Chris Tsang", email = "tyt2y7@gmail.com" }]