Document standard icons and glyphs

[lucaswoj]

In #241 we added standard icons and glyphs to all our styles 🎉

This standard set should be documented somewhere. This repo's README.md would be good or there might be a better place.

ref http://stackoverflow.com/questions/36131298/mapbox-gl-js-available-icons

[amyleew]

README.md update with #304 merge.

[lucaswoj]

I'm getting feedback from our users that we need to make the standard icon set easier to navigate. Creating a reference that shows all icons and their names in one place would be a good step.

[samanpwbb]

Are
https://github.com/mapbox/maki/blob/master/layouts/streets.json or https://www.mapbox.com/maki-icons/#editor (click new, select streets set) helpful?

Ideally we maintain this data in one place. The layout/streets file can be required via npm.

[lucaswoj]

Are
https://github.com/mapbox/maki/blob/master/layouts/streets.json or https://www.mapbox.com/maki-icons/#editor (click new, select streets set) helpful?

Both are helpful, neither is quite what our users are looking for. Imagine yourself as a Mapbox user. You'd want to see:

• all icons in one place
• the name of each icon as it should be used in the style

https://github.com/mapbox/maki/blob/master/layouts/streets.json doesn't show what the icons look like

https://www.mapbox.com/maki-icons/#editor requires some interactions before the icons are visible, doesn't show icon names except on hover, and doesn't show icon names as used in styles (these have a .svg suffix)

Ideally we maintain this data in one place. The layout/streets file can be required via npm.

Agree.

[samanpwbb]

I recommend that we add a section to the default style pages (https://www.mapbox.com/studio/styles/mapbox/streets-v9/share/) that lists all icons in a way that is convenient for developers.

[lucaswoj]

I am uncomfortable putting a login page between users and documentation for open source software.

A markdown table within the mapbox-gl-styles README.md documentation would go a long way towards making our default sprites easy to nagivate.

[samanpwbb]

We can create a new page for default icon documentation and link to it from wherever necessary so the page is open.

[lucaswoj]

Closed by #318