* Fixed several of the issues and nits from PR:

* Moved margin between header and file name to header, so when content was scrolled, the header would remain more separate
* Made build-time and runtime overlays better match
* Secondary error <pre> style now uses yellow bg instead of red
* 'Scrollable Header' (see above comment to why this is necessary) but I did increase the max-height from 35% to 50%.
* Fixed header and 'X' button vertical alignment

* Temporary stack margin fix

* Move "N errors" to the top

* Tweaked overlay styles

* Tweaked pre-style

* Clicked to background overlay dismiss

* Tidied up styles tobe more mobile Safari friendly

* Re-enabled pre-wrap

* Margin fixes

* Base font-size 10 -> 11px

* Error overlay is full-screen now based on feedback

* Make "N errors on the page" visible again

* Fix bottom margin of frame location and lack of tab nav

* Add tooltip to close button

* Bring compile error styles closer to runtime overlay

* s/when/if/

* ༼ つ ◕_◕ ༽つ stack-frame-overlay

* Fix linting

* Remove auto overlay

* Fix e2e

* Pull in the rest

* Appease flow

* Correct dep

* Remove old repo references

* Check flow on test

* Test overlay in e2e

* Add cross env

* Rename package

* Make sure it gets built post-install

* Update the README

* Remove extra builds now that there's a postinstall script

* Revert "Remove extra builds now that there's a postinstall script"

This reverts commit 8bf601db.

* Remove broken script

* Fix some dev ergo