Don't bias README.md towards distros

[jyn514]

Location

README.md

Summary

Currently, the top-level readme looks something like this:

# THE RUST PROGRAMMING LANGUAGE

blah blah boilerplate

this readme is for users, not contributors

TABLE OF CONTENTS

read this if you are a user

HERE ARE 500 LINES ABOUT HOW DISTROS SHOULD COMPLE RUSTC FROM SRC
IT GOES ON FOR A LONG TIME
IT HAS CODE SNIPPETS AND EVERYTHING
```
./configure
```
LOOK AREN'T THESE CODE SNIPPETS SO INVITING
```
make
```

blah blah licensing

This makes it really easy for someone to quickly look at the readme, see that it suggests ./configure, and run that locally. Unfortunately, that will be the wrong thing to do for 99% of contributors, because configure sets profile = "dist" at the top. Additionally, it's not really serving actual users of rust, who almost certainly don't want to compile from source (they either want to install from rustup or from their distro).

I suggest moving the vast majority of the README into a separate file, perhaps called INSTALLING_FROM_SOURCE.md, and making the top-level README only contain the sections preceding "Installing from source" and following "Notes". That should make it a lot more clear that it's not intended for either users or devs.

@rustbot label +E-easy +E-help-wanted

[crlf0710]

I submitted a PR to move the contents to forge. After it's merged and deployed maybe we could just link to that.

[jyn514]

hmm, ok. I worry that it will get out of date there since it won't show up with ripgrep, but it seems better than having it front and center in the readme.

[homersimpsons]

Looks like this can be closed with #119189