Move Nmag webpages

[fangohr]

Move https://nmag.soton.ac.uk/nmag/index.html to https://fangohr.github.io/nmag.github.io

The sources are available at https://github.com/fangohr/nmag-www

(This is a copy of https://bitbucket.org/fangohr/nmag-www/src/www/, but the suggestion is to take the github copy of the repo as the authoritative one in the future.)

• This must be made to compile (should be reasonable; needs python 2)
• ideally in a container (Docker) so it is easier for others to repeat
• Content must be updated but is separate issue (Update links in Nmag webpage #3)
• static html of the compiled version (than rest2www creates) to be put into the repo https://github.com/fangohr/nmag.github.io so that it appears automatically on https://nmag.github.io

[mhanberry1]

Added docker compilation:
fangohr/nmag-www#1

[mhanberry1]

See fangohr/nmag.github.io#1 for status on migrating code to https://nmag.github.io