Fixing the issue #3292

This change fixes the issue #3292. The details were mentioned in the comments to the issue.
Update Response.php

typo
first approach to a PDF guide
generate PDF file chapters from README.md structure
Improve array support for "data" attribute in renderTagAttributes()
Add #3597 to CHANGELOG.md
Merge pull request #3597 from armab/patch-1

Improved array support for "data" attribute in renderTagAttributes()
Fixes #3564
Hotfix for #3597
Merge pull request #3600 from armab/patch-2

Hotfix for #3597
Update rest-quick-start.md: highlight automatic pluralization

This is probably not expected given the other naming conventions within Yii, so highlight this feature for beginners.
Update rest-quick-start.md: grammar

bad grammar
Merge branch 'patch-2' of github.com:it3rmit/yii2 into it3rmit-patch-2
Fixes #3292: Fixed dropdown widgets rendering incorrect HTML
Merge branch 'it3rmit-patch-2'
Merge pull request #3603 from myqlarson/patch-3

Update rest-quick-start.md: highlight automatic pluralization
minor update [skip ci]