add cvmfs_config reload step to GPU instructions, and add tip about EESSI-specific config files

[bedroge]

No description provided.

[boegel]

@bedroge Maybe you can also tackle the two small issues I noticed:

• There's a trailing : in the subsection title Runtime support when using EESSI in a container: which shouldn't be there
• Rendering of the bullet list in Enabling runtime support section is broken, needs an empty line above/below bullet list;

[boegel]

This should perhaps be a subsection that we can link to, instead of a note.

And perhaps this should go above, even above Configuring runtime support?

[bedroge]

I'm not sure, it's quite technical and many users may not really care about how this works. Being able to link to it could be useful though.

[ocaisa]

This can be done in a follow-up PR (if it is really necessary). We should get this in so that we can start pointing people towards it.

[bedroge]

@bedroge Maybe you can also tackle the two small issues I noticed:

• There's a trailing : in the subsection title Runtime support when using EESSI in a container: which shouldn't be there
• Rendering of the bullet list in Enabling runtime support section is broken, needs an empty line above/below bullet list;

Fixed in befb5e1 and d889e54.

[ocaisa]

LGTM