[ Documentation ] vectorgen XML file : output_format

[Alice Q.]

https://github.com/nasa-gibs/onearth/blob/master/src/vectorgen/README.md

When describing the contents of the configuration file, it is said that "output_format" value should be either "ESRI Shapefile" or "MRF-MVT".

Second value is wrong, it should be "MVT-MRF" (oe_vectorgen.py line 416 will "fail")

[Joe T. Roberts]

Thanks for reporting the discrepancy. The README has been corrected.