Archive old documentation versions as artifacts

[Ekhorn]

User story

As developer I only want to build the next documentation versions (optionally some older versions), to reduce build times and memory usage.

Description

When I started the latest documentation (1.17.3 at the time of writing) it was using 6.3GB of my RAM and took a few minutes to build.

We should consider building for a couple versions in case something needs to be documented after already being released. Ideally we would create a mechanism that can patch older versions when specified.

Acceptance criteria

• Old documentation versions should be built and stored as artifacts.
• npm start should only build next (and optionally a few older versions).
• The pipeline should generate artifacts for built documentation versions through npm build.
• Investigate what the documentation version build limit should be.

Implementation

Maybe we can just empty the versioned_docs once releasing and patch older versions by creating a new copy for that version in the versioned_docs dir.

[wborn]

#146 has sped up the build which alleviates this issue for now. However over time it will become a bigger issue again.

Often Docusaurus websites only build recent versions and use a static archive of previously build versions.

Some examples having an "All versions" option at the bottom of the versions drop down which makes older versions accessible:

• Docusaurus documentation has an All versions option
• Rancher documentation has an All versions option