Version 4.6.1

Describe the bug

Web Chat does not work in IE11; with errors:

To Reproduce

Steps to reproduce the behavior:

1. Run 01.b.getting-started-es5 sample
2. Open in Internet Explorer
3. Open console
4. See errors match screenshot above

Expected behavior

Web Chat should work in IE11

Additional context

It looks like the bump of remark caused this issue due to is-plain-obj not being transpiled. unified, a child of remark, uses is-plain-obj even though the package is intended for node environments, not the browser. To get rid of this problem we'll have to find which version of remark doesn't ultimately use is-plain-obj version 2.0

TL:DR; de-bump remark

[Bug]