[icons] feat: add stadium-geometry + area-of-interest, edit send-message

[candyyyji]

Fixes #0000

Checklist

• Includes tests
• Update documentation

Changes proposed in this pull request:

Added new icon for:

• area of interest
• stadium

Edited icon for:

• send message

Reviewers should focus on:

Everything renders ok and right files were changed

Screenshot

[adidahiya]

@candyyyji the send-message icon doesn't look any different? am I missing something?

current live docs:

this PR preview:

but the new ones look fine:

btw are we sure this minimal representation of a stadium will be clear enough? IMO it looks like a generic oval, something to do with shapes and drawing rather than a location. have we considered a less minimal representation of a stadium?

[candyyyji]

allen asked me to move two vertices by half pixel so the corners snapped to whole pixels... you shouldn't be able to see any difference... 😬

[adidahiya]

cool. I'm still curious about my question from above:

have we considered a less minimal representation of a stadium?

[candyyyji]

oh sorry i missed that question!
it's for "holding pattern" in our application https://en.wikipedia.org/wiki/Holding_(aeronautics), but holding pattern isn't generally applicable elsewhere so i found that the mathematical word for this shape, which is "stadium" https://mathworld.wolfram.com/Stadium.html

[candyyyji]

we could change the name of this icon though! in case in future we need an actual stadium?

[adidahiya]

Discussed offline, renamed to "stadium-geometry"