Update issue templates

[RyanCavanaugh]

Goals of this PR:

• Make the repo more "welcoming" - yelling at people in the template isn't friendly, and doesn't seem to have affected behavior in any measurable sense
• Make the templates less "wall-of-text"y by using markdown header sections and emoji to more clearly visually break apart each section
• Reorder the sections to create a "funnel" that encourages people to do things in the right order (search, regress, then describe)
• Add a new template for the common case of DOM/lib updates
• Encourage filers to explicitly identify regressions, since we care a lot about these, and also funnels "has always been this way" bugs into the FAQ more explicitly rather than upfront

I removed the "related issues" since I have rarely found it to be useful.

[DanielRosenwasser]

🏌🏻‍♂️

?

[RyanCavanaugh]

I had to zoom my display way in to parse that emoji

[DanielRosenwasser]

I actually kind of always disliked the ordering because what I tend to do is follow the template, and I want to just paste in the existing behavior. That means I have to jump down to the "actual behavior" section first, massage that, and then copy/paste that into the "expected behavior" section. I'd love if we were open to switching to "Current Behavior" followed by "Expected Behavior" or "Proposed Behavior"

[RyanCavanaugh]

Agree; swapped

[DanielRosenwasser]

I'd tend to suggest that motivation comes first - this is really the way I expect to read about features as a user, and it's the way that our team considers features. A new proposal should consider that first.

[RyanCavanaugh]

Agree

[DanielRosenwasser]

Is there much of a difference between "Use Cases" and "Motivating Example"?

[RyanCavanaugh]

I like having more places for people to provide color

[orta]

Noting to self to update the version of this in the Playground once this is merged