Packages the distutils stdlib module as a standalone package,
```
377K distutils.data
221K distutils.data.br
19K distutils.js
```
to reduce the minimal pyodide size.

Part of #1542 

This also,
 - adds documentation on what's supported or not in the stdlib
 - makes a few changes to `pyodide_build/buildall.py` to be able to add such stdlib packages as a dependency in other packages (which didn't work before). For instance, until there is a release with https://github.com/pypa/packaging/pull/396 micropip has a dependency on distutils.
Unvendor distutils. Packages the distutils stdlib module as a standalone package,
```
377K distutils.data
221K distutils.data.br
19K distutils.js
```
to reduce the minimal pyodide size.

Part of #1542 

This also,
 - adds documentation on what's supported or not in the stdlib
 - makes a few changes to `pyodide_build/buildall.py` to be able to add such stdlib packages as a dependency in other packages (which didn't work before). For instance, until there is a release with https://github.com/pypa/packaging/pull/396 micropip has a dependency on distutils.
#release-notes .badge {
    margin-right: 5px;
    opacity: 0.7;
}

code {
    font-size: 100% !important;
}


.section > h3 {
    /* shrink h3 a bit, was ~1.8em */
    font-size: 1.65em;
}

.section > h4 {
    /* shrink h4 a bit, was 1.44em */
    font-size: 1.3em;
}

/* Remove "captions" in text table of contents, keep subsections in sidebar */
.toctree-wrapper > .caption {
    display: none;
}

#release-notes .badge {
    margin-right: 5px;
    opacity: 0.7;
}

code {
    font-size: 100% !important;
}


.section > h3 {
    /* shrink h3 a bit, was ~1.8em */
    font-size: 1.65em;
}

.section > h4 {
    /* shrink h4 a bit, was 1.44em */
    font-size: 1.3em;
}

/* Remove "captions" in text table of contents, keep subsections in sidebar */
.toctree-wrapper > .caption {
    display: none;
}
