update readme with remaining modules (so far)

README.md

@@ -1,19 +1,11 @@
-This repository factors out an opinionated selection of internal packages and functionality from the Go standard
-library. Currently this consists mostly of packages and testing code from within the Go tool implementation.
+This is a fork/hacked up version of https://github.com/rogpeppe/go-internal as a toplevel testscript/ minimal module
 
 Included are the following:
 
-- dirhash: calculate hashes over directory trees the same way that the Go tool does.
-- goproxytest: a GOPROXY implementation designed for test use.
-- gotooltest: Use the Go tool inside test scripts (see testscript below)
 - imports: list of known architectures and OSs, and support for reading import statements.
-- modfile: read and write `go.mod` files while preserving formatting and comments.
-- module: module paths and versions.
 - par: do work in parallel.
-- semver: semantic version parsing.
 - testenv: information on the current testing environment.
-- testscript: script-based testing based on txtar files
-- txtar: simple text-based file archives for testing.
+- testscript: script-based testing based on txtar files (now toplevel module)
 
 # Links