adjust decorate-terms behaviour

[longhotsummer]

1. instead of links, just handle click events
2. style with dotted underline

this makes term references less obtrusive and means they aren't included in copy-and-paste, in which they're useless any way.

The substantive changes:

• https://github.com/laws-africa/law-widgets/pull/276/files#diff-005391dc7bc423d3fec7b6944402cf6bdfaae1fae382912684361c4e5c6a51ec
• https://github.com/laws-africa/law-widgets/pull/276/files#diff-b2b9cbce51c04b1bf0504b720b0469f8a6433e648993ff6b5901a1e71c9872c1

Also:

• upgrade to stencil 4
• remove a whole bunch of unused/unnecessary dependencies and scripts

[longhotsummer]

Closes #275