Lock mkdocs-material to v4.6 for Netlify
Lock mkdocs-material to v4.6 for Netlify

Netlify's pip provides mkdocs v1.0, but not v1.1, which is needed for
mkdocs-material v5.x.

Signed-off-by: onox <34c1d3d2d1347bea60a26f46574de21a7a79b6d5@gmail.com>

onox/orka