[Doc] Recommend shallow clone for Win dev installation [skip CI]
[Doc] Recommend shallow clone for Win dev installation [skip CI]

Update installation instructions for development on Windows to recommend a shallow clone of the engine repo.

Former-commit-id: a777959d7df61b83e75198e41f15ddca0b62dff9
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine