docs: update README with local installation instructions

README.md

@@ -2,26 +2,39 @@
 
 # Stainless-ByzCoin Demonstrator
 
+Stainless is a tool to help designing highly reliable programs in Scala. Using Formal Verification, it will check
+whether the system behaves according to how it was specified, or if it will deviate in unexpected ways.
+Logical errors, security vulnerabilities and other defects can therefore be detected before the program is deployed.
+
+Please refer to the [project's showcase](https://factory.c4dt.org/showcase/stainless-for-smart-contracts/presentation)
+for additional information on the project's theoretical background.
+
 Steps to run locally:
 
-You first need to generate the node's configs
-```
-make configs
-```
+Install `Go` by [following the official instructions for your OS](https://go.dev/doc/install), then
+download the appropriate `Protocol Buffers` [archive for your architecture](https://github.com/protocolbuffers/protobuf/releases)
+and extract it into this directory.
+
+You need to add the extracted binary to the path your OS is searching for executables, e.g. via
 
-If you want our prebuilt images
 ```
-docker-compose pull
+PATH=$PATH:$(pwd)/bin
 ```
-Else if you want to build the images yourself
+
+in Linux.
+
+Generate the node's configs
+
 ```
+make configs
 make webapp-proto
 docker-compose build
 ```
 
 Launch it with
+
 ```
 docker-compose up
 ```
 
-And open a browser to http://localhost:80/stainless-demo/
+And open a browser to http://localhost:80/stainless-demo/.