Fix README.md grammar "e.g.,"
Fix README.md grammar "e.g.,"

A punctuation mark always precedes e.g. In American English a comma
should follow e.g. The list of examples following e.g. should not be
exhaustive.

Reference: https://en.wiktionary.org/wiki/e.g.

alucard0134/Pomf,pomf/pomf,ewhal/gpomf,alucard0134/Pomf,pomf/pomf,pomf/pomf-php,alucard0134/Pomf