Moved improved ‘Inventory’ section of ‘README.md’ into separate ‘Inventory.md’ file

[regexident]

The one inventory reference to rule them all! 🤘🏻

Disclaimer: This inventory assumes a post-completion state of https://github.com/mattt/Surge/issues/106.

Notable mention: Sprinkled all over the file you find <!-- FIXME: … --> comments addressing API inconsistencies that revealed themselves during the document's assembly.

[mattt]

👏

This is wonderful. It's really nice to have a summary of all of the available functions and operators all together like this.

The only question I have is, why move this out of README? As much as I appreciate organizing information, there's (unfortunately) a very high cost to splitting up information like this. Everyone sees the README, but almost nobody will find a Github Wiki page or a Markdown file in a docs directory — even when it's linked from the README. Folks seem not to mind at all scrolling through a long README, and the use of <details> and a TOC alleviate much of the cost.

What do you think about keeping all of this great information in the README?

[regexident]

Those are some more than valid points! I'll move it back into README.

The reason I extracted it was that I feared it would add too much bloat to the README (as the use of <details> only later occurred to me while working on the file) and hide potentially important information from the bottom of the README (which of course can be avoided easily by simply pushing the inventory to the very bottom of the document).