Update README docs (#2417)

* Update README docs

* Fix typo

* Fix typo

* Update waspc/README.md

Co-authored-by: Martin Šošić <Martinsos@users.noreply.github.com>

---------

Co-authored-by: Martin Šošić <Martinsos@users.noreply.github.com>

Author: komyg

waspc/README.md

@@ -39,16 +39,16 @@ the project. The best way to install it is via
 is a convenient way of installing and selecting versions of `cabal`, `hls` and
 `ghc`.
 
+:warning: On Mac, we recommend using the official [ghcup](https://www.haskell.org/ghcup/) installer over Homebrew, as it works out of the box.
+
 In [cabal.project](cabal.project) we're explicitly saying what compiler version
 to build Wasp with.
 
 ```cabal
 with-compiler: ghc-x.y.z
 ```
 
-Ensure that you have this [ghc
-version](https://downloads.haskell.org/ghc/latest/docs/html/users_guide/intro.html#ghc-version-numbering-policy)
-installed.
+Please ensure that you have this ghc version installed.
 
 ### Repo
 
@@ -69,7 +69,9 @@ If that is the case, relax and feel free to get yourself a cup of coffee! When s
 
 :warning: You may need to run `cabal update` before attempting to build if it has been some time since your last update.
 
-:warning: If you are on Mac and get "Couldn't figure out LLVM version!" error message while building, make sure you have LLVM installed and that it is correctly exposed via env vars (PATH, LDFLAGS, CPPFLAGS). The easiest way to do it is by just running `brew install llvm@13`, this should install LLVM and also set up env vars in your `~/.zshrc`.
+:warning: If you are on Mac and get "Couldn't figure out LLVM version!" error message while building, make sure you have LLVM installed and that it is correctly exposed via env vars (PATH, LDFLAGS, CPPFLAGS). The easiest way to do it is by just running `brew install llvm@13`, this should install LLVM and also set up env vars.
+
+:warning: If the LLVM error persists even after its installation, you may need to manually add it your PATH. To do this, you should add the following to end of your shell rc file (e.g. *~/.bashrc* or *~/.zshrc*): `export PATH="/opt/homebrew/Cellar/llvm@13/13.0.1_2/bin/:$PATH"`.
 
 ### Test