Docs need details on prerequisites/requirements to install

[webvictim]

e.g.:

• Minimum version of Go is 1.12
• You need mkdocs > 0.16.3 to build the docs -- You also need the markdown-include-lines plugin

[pierrebeaucamp]

fyi make install-docs installs dependencies for generating docs, as long as pip is available

[webvictim]

🤔

I guess I must have missed that in the Makefile