Fix punctuation

[zekiakyol]

• It fixes punctuations, typos, and grammar in the book's plaintext, cover-to-cover.
• Punctuation corrections are mostly about missing commas. The rest is about missing dashes in adjectives which are combination of two words.
• In "Files changed" tab on GitHub, following 3 changes are not highlighted (in red/green) properly for a reason but
  • in internals.Rmd it changes:
    • gridlines,and to gridlines, and
    • reference based classes to reference-based classes
  • in networks.Rmd it changes:
    • In order to show network topology to In order to show network topology,

[hadley]

Thanks!

[zekiakyol]

You are welcome!