Mention zig in readme and introduction page (#2457)

Zig is the easiest way to build a manylinux wheel, much easier than the
manylinux docker container, so we should point users to it more
prominently.

README.md

@@ -204,7 +204,7 @@ There's a `maturin sdist` command for only building a source distribution as wor
 
 For portability reasons, native python modules on linux must only dynamically link a set of very few libraries which are installed basically everywhere, hence the name manylinux.
 The pypa offers special docker images and a tool called [auditwheel](https://github.com/pypa/auditwheel/) to ensure compliance with the [manylinux rules](https://peps.python.org/pep-0599/#the-manylinux2014-policy).
-If you want to publish widely usable wheels for linux pypi, **you need to use a manylinux docker image**.
+If you want to publish widely usable wheels for linux pypi, **you need to use a manylinux docker image or [build with zig](#use-zig)**.
 
 The Rust compiler since version 1.64 [requires at least glibc 2.17](https://blog.rust-lang.org/2022/08/01/Increasing-glibc-kernel-requirements.html), so you need to use at least manylinux2014.
 For publishing, we recommend enforcing the same manylinux version as the image with the manylinux flag, e.g. use `--manylinux 2014` if you are building in `quay.io/pypa/manylinux2014_x86_64`.

guide/src/distribution.md

@@ -43,7 +43,7 @@ include = [{ path = "path/**/*", format = "sdist" }]
 
 For portability reasons, native python modules on linux must only dynamically link a set of very few libraries which are installed basically everywhere, hence the name manylinux.
 The pypa offers special docker images and a tool called [auditwheel](https://github.com/pypa/auditwheel/) to ensure compliance with the [manylinux rules](https://peps.python.org/pep-0599/#the-manylinux2014-policy)).
-If you want to publish widely usable wheels for linux pypi, **you need to use a manylinux docker image** or [build with zig](#use-zig).
+If you want to publish widely usable wheels for linux pypi, **you need to use a manylinux docker image or [build with zig](#use-zig)**.
 
 The Rust compiler since version 1.64 [requires at least glibc 2.17](https://blog.rust-lang.org/2022/08/01/Increasing-glibc-kernel-requirements.html), so you need to use at least manylinux2014.
 For publishing, we recommend enforcing the same manylinux version as the image with the manylinux flag, e.g. use `--manylinux 2014` if you are building in `quay.io/pypa/manylinux2014_x86_64`.