v0.18.0

Changelog

e405b66 Improve data types example
5db6eb2 HOT: update for OpenStack Wallaby
89642fa Substitution: validate properties and attributies
952b651 Substitution: support property-to-input mapping
edbed1e Documentation overhaul
3122110 Merge pull request #46 from amarchese96/main
1b48d57 Change field names in file dgraph.js of Dgraph example
698fa4c Fixes to Dgraph example
c2871fc Improve mapping compilation for substitution
5603cf2 Begin work on properly supporting mappings
2257719 Don't colorize problems if not in terminal
4b92464 Major refactor to documentation and profiles