Improve buidling instructions

[GulgDev]

Hello! Recently I was contributing to Binaryen on Windows and building was a disaster for me. I just couldn't get the build tools to work. So, maybe, README needs to be extended to include the following:

1. Use the same build commands as in CI. Build commands from the README didn't work for me, so I just copy-pasted everything from CI.
2. Update testing instructions. Getting tests to work was even harder. For example, they don't work on Windows natively (you need to use Git Bash, for example). Also, I had issues when installing the required tools. I had to completely uninstall SpiderMonkey engine from my system, as there was no option to exclude it from the tests.
   Thanks!
3. Include linting in documentation. CI failed for me multiple times because of linting and it wasn't even mentioned in the README.

P.S. Maybe I'm just stupid and everything works fine for other people, so I haven't opened an issue and instead started a discussion

[kripken]

Sorry about this - the main reason is probably that none of the main devs use windows.

If you can open a PR with improvements to the readme based on what you found, that would be great!

[GulgDev]

OK. Should I better update README and improve the previous guide or instead make changes in a separate place?

[GulgDev]

Also, I would like to discuss this with some of the maintainers, because I might be missing something.

[kripken]

Updating the readme where it is makes sense to me.

[GulgDev]

So, I have some questions that I was unable to found an answer to. First of all, I can't seem to find a way to perform a single test on binaryenjs. Secondly, why are commands in CI differ from the ones in the README file?

[kripken]

Looks like that was an oversight in binaryenjs. I opened #7483 which adds --filter support there, so you can run a specific subset of tests.

About CI/Readme differences, I imagine that the Readme is just out of date. What works in CI is what matters - we should update the readme.

[kripken]

Did you also apply the change in the PR? (it hasn't landed yet)

The example works for me, with the PR.