Improve the StageXL template description

[kwalrath]

The StageXL template isn't getting many users. Let's see if improving the description helps.

Here's the current description:

• web-stagexl - A basic 2D canvas app with StageXL. (command line)
• Simple StageXL Application - a basic 2D canvas app with StageXL. (IDE)

Although the new IDE description can't be much longer, we can subtract characters from the left side of the - to add to the right side. We don't need to mention "StageXL" on the right side. Possible words to use on the right side:

• WebGL
• game
• animation

Maybe we could have something like:

• StageXL Web App - a starting point for WebGL-based animation and games.

What do you think, @filiph, @Tomucha, and @bp74?

The other template descriptions, for reference:

• Console Application - a command-line application sample.
• Dart Package - a starting point for Dart libraries or applications.
• Shelf Web Server - a web server built using the shelf package.
• AngularDart Web App - a web app with material design components.
• Low-level HTML App - a bare-bones web app.

[Tomucha]

@kwalrath Thanks for keeping my baby alive!

WebGL evokes 3D, but StageXL is 2D only.

I vote for:
StageXL Web App - a starting point for 2D animation and games

[kwalrath]

Fixed in #403.