Configurable tags

[cutandpastey]

This PR adds the ability to construct notes of different tags i.e <gu-flag></gu-flag>.

QA

Test all note functionality on the example page using F9, ensure gu-flag tags are constructed.

[robinedman]

Is this supposed to be a first step or a more complete "flag & correct" thing? Would help to know when reviewing it. If it's literally what the description says it looks good to me :) but otherwise I can immediately see some issues!

Such as:

• This includes "flag" but not "correct".
• You're able to create notes within flags (and the other way around), which seems a bit odd.

[cutandpastey]

Iv'e added tests and fixes for note collision, so if @robinedman is happy can we merge?

[robinedman]

It's still possible to create a note within a flag and vice versa so I'm not sure if the collision stuff is working.

A couple of more things:

• If you create a note and a flag next to each other, then you can't put the cursor between them.
• If you flag some text, then unflag a part of it, then note the whole thing you'll end up with flags and notes next to each other (probably "correct" in terms of the current merging behaviour but maybe disallow things like this?)

[cutandpastey]

@robinedman note collision should now be fixed.

[robinedman]

Can't test this atm. The build fix broke the build (https://github.com/guardian/scribe-plugin-noting/commit/10489c556148864a8ae071ab2b470dd6451cac36).

Now npm run build doesn't build the JS anymore for some reason.

[cutandpastey]

Fixed

[robinedman]

Works really well now! :+1:

[cutandpastey]

Cool, I'll wait for travis before releasing.

[cutandpastey]

Im reverting this to get the fix for https://github.com/guardian/scribe-plugin-noting/issues/75 out