Add new TC39 proposal: Import Text

[eemeli]

This adds a new proposal that I'd like to advance at TC39. As per the instructions, I've gotten prior approval from @dminor and @martinthomson to submit this.

I've left out the outline of a proposed solution and further sections, as doing so is required for a TC39 proposal, but it should be noted that this particular proposal is a direct reaction to the Import Bytes proposal advancing rapidly at TC39. Therefore, the expected form of the solution would be to allow for this to work:

import text from "path/to/file.txt" with { type: "text" };

If possible, I'd like to present this to TC39 at its next meeting, for which the agenda submission deadline is on 7 November.

[eemeli]

@dminor Given the process change in #58, should I add the elided sections to this PR?

[dminor]

@dminor Given the process change in #58, should I add the elided sections to this PR?

Yes, please do.

[eemeli]

@dminor Done. Because I prepared the commit previously, GitHub's timeline puts it before our comments above.

[tantek]

This needs an explicit user-perspective benefit summary sentence or two at the top per our Explainer sections. Like does it improve performance for users, or reliability (fewer bugs), or some other preferably more specific user-centric improvement?

[tantek]

Thank you, this is a good start. Let's land and iterate.