Add 'Email' icon to social icon library

[kwm14]

Request to @pmahnke from team curating https://cn.ubuntu.com/

Add an email social icon to Vanilla, so the team can use to share content via email.

• https://docs.vanillaframework.io/patterns/icons/#social

[kwm14]

Current icons available on the asset server

circa 2015

circa 2016

circa 2018

None of these really match our current style, will speak with @waynecrosby @marcush to see if they have an updated one, or whether we need to propose a new one to the icon designers 👍

[kwm14]

Updated style provided by @waynecrosby in a recent illustration...

• https://assets.ubuntu.com/v1/c4b290c8-Contact+us.svg

But we will need to re-look at it at a smaller icon size 👍

[kwm14]

@waynecrosby I've updated our social icons to use official brand assets.

Now seeing them in situ I don't think the email icon will fit within the social set, maybe we need to revert the icon to fill rather than an outline. What do you think?

[waynecrosby]

@kwm14 I think you're right, a solid version will work best to fit with the others. What pixel size are you using?

[kwm14]

@kwm14 I think you're right, a solid version will work best to fit with the others. What pixel size are you using?

👍 40px