Update content.json

Small addition under "make" for Infrastructure.
Update content.json

Made several small edits to "make" copy + content under Infrastructure, and realised I put the original edit in Web Mechanics (which on CTRL+F was the first instance of the word Infrastructure, #fail!). Modified to fix this too.
Merge pull request #861 from keyboardkat/patch-8

Fixes Bug 1030246 - Consider adding these to the infrastructure resources page