Remove reference to old install script

README.md

@@ -29,21 +29,8 @@ cargo install --git https://github.com/paritytech/polkadot --tag <version> polka
 
 ### Build from Source
 
-If you'd like to build from source, follow these instructions.
-
-#### Quick Setup
-
-Install all the required dependencies with a single command. (Be patient, this can take up to 30
-minutes):
-
-```bash
-curl https://getsubstrate.io -sSf | bash -s -- --fast
-```
-
-#### Manual Setup
-
-First install Rust. You may need to add Cargo's bin directory to your PATH environment variable.
-Restarting your computer will do this for you automatically.
+If you'd like to build from source, first install Rust. You may need to add Cargo's bin directory
+to your PATH environment variable. Restarting your computer will do this for you automatically.
 
 ```bash
 curl https://sh.rustup.rs -sSf | sh
@@ -58,11 +45,9 @@ rustup update
 Once done, finish installing the support software:
 
 ```bash
-sudo apt install build-essential git clang libclang-dev pkg-config libssl-dev 
+sudo apt install build-essential git clang libclang-dev pkg-config libssl-dev
 ```
 
-#### Build
-
 Build the client by cloning this repository and running the following commands from the root
 directory of the repo: