Fixed a typo in the computation rule for W-types.
Added "Fixed a tpyo in the computation rule for W-types" to the errata.
Improved errata.
...
Merge pull request #589 from mr-/master

Typo in Section 5.3 W-types.
remove spurious extra %
formatting
Mark Errata (auto)
Updated Reading_HoTT_in_Coq for Coq 8.4pl3
clarify ex 9.4, close #590
Merge pull request #592 from mikeshulman/pre2categories

clarify ex 9.4, close #590
Merge branch 'master' of https://github.com/HoTT/book

sync with upstream