Add section to docs explaining our stance on validators

BS3 commits: f5a05fe9e96bb0ee877e4b19149b9512eeb52956
Address 14541 by tweaking badge docs

BS3 commits: c20d00cf058a85dea22c6073623e93549bce32e0
Update dependencies.

BS3 commits: 5befcb991cc62b338abc0401e6496c3866000a12
Run `grunt`.

BS3 commits: 5b9fcea9f2541a3adcbea5dff5bafaf956c7195e