fix: README Sprite example

[coolryanc]

Hi,

Looks like the method of PIXI.Sprite only has from now.
Ref: http://pixijs.download/release/docs/PIXI.Sprite.html#.from

[codecov]

Codecov Report

Merging #110 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #110   +/-   ##
=======================================
  Coverage   95.67%   95.67%           
=======================================
  Files          11       11           
  Lines         231      231           
=======================================
  Hits          221      221           
  Misses         10       10

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9d1fa7c...af6a7c6. Read the comment docs.

[michalochman]

Hi @ryanc1993, it's a Texture method, not Sprite, and it is only true for PixiJS v5.

This library is compatible with PixiJS v4 as well, but I will merge this as we probably need to keep documentation updated with the newest versions of dependencies. Can you update all instances of this?

[coolryanc]

Okay, I will try other examples at README document and help update it. 👍

[michalochman]

Done comprehensively in #123