Fix non-existent CRS example in Example 3

[jakubklimek]

http://www.opengis.net/def/crs/EPSG/0/102100 doesn't exist to be conformed to

Originally posted by @nmtoken in #166

In this example.

Proposition is to remove it. @nmtoken any other suggestions?

[nmtoken]

Perhaps could change to https://spatialreference.org/ref/esri/102100/