BLD Add DISTDIR variable. ### Description

Adds `DISTDIR` env variable that points to the directory where libraries should be copied to when building shared libraries with recipe.

### Checklists

- [x] Add new / update outdated documentation

# Pyodide packages

This folder contains the list of packages built in pyodide.

Packages are built with the Python build system
using `pyodide_build/buildall.py` and `pyodide_build/buildpkg.py` scripts.
See the [documentation](https://pyodide.org/en/stable/development/new-packages.html) for more details.

# Pyodide packages

This folder contains the list of packages built in pyodide.

Packages are built with the Python build system
using `pyodide_build/buildall.py` and `pyodide_build/buildpkg.py` scripts.
See the [documentation](https://pyodide.org/en/stable/development/new-packages.html) for more details.
