Add more README.md files

README.md

@@ -0,0 +1,22 @@
+# Xfunc Implementation
+
+Extending De-/Refunctionalization to the Lambda Cube
+
+## Project overview
+
+```text
+├── app                     CLI application
+├── examples                Example code in the object language
+├── ext/vscode              VSCode extension
+├── lang                    Language implementation
+│   ├── core                Core (typechecker, evaluator)
+│   ├── lowering            Lowering concrete to abstract syntax tree
+│   ├── parser              Parse text to concrete syntax tree
+│   ├── printer             Print abstract syntax tree to text
+│   └── syntax              Syntax tree definitions
+├── lsp                     LSP language server implementation
+├── scripts                 Utility scripts
+└── web                     Web demo application
+```
+
+Please refer to the `README.md` files in the individual subprojects for further information.

app/README.md

@@ -0,0 +1,31 @@
+# CLI application
+
+## Requirements
+
+* [Rust and Cargo](https://www.rust-lang.org/tools/install)
+
+## Build
+
+```sh
+cargo build
+```
+
+## Run
+
+Start interactive REPL:
+
+```sh
+cargo run
+```
+
+Run a file:
+
+```sh
+cargo run -- run <filepath>
+```
+
+Print available command-line options:
+
+```sh
+cargo run -- --help
+```

ext/vscode/README.md

@@ -1 +1,44 @@
 # VSCode extension
+
+## Requirements
+
+* [VSCode](https://code.visualstudio.com/Download)
+* [Node.js](https://nodejs.org/en/download) and [npm](https://www.npmjs.com/package/npm)
+* [vsce](https://www.npmjs.com/package/vsce)
+
+To install `vsce` via `npm`, run:
+
+```sh
+npm install -g vsce
+```
+
+## Develop
+
+Open this folder in VSCode:
+
+```sh
+code .
+```
+
+Open the "Run and Debug" tab (`Ctrl+Shift+D`).
+Select the "Extension" run configuration.
+
+Press `F5` or the "Start Debugging" button in VSCode.
+
+## Package
+
+To package the extension, run:
+
+```sh
+vsce package
+```
+
+This should create a file named `xfn-0.0.1.vsix`.
+
+## Install
+
+To install the extension in your local VSCode environment, run:
+
+```sh
+code --install-extension xfn-0.0.1.vsix
+```

lsp/README.md

@@ -0,0 +1,3 @@
+# LSP Language Server
+
+Rust library providing a language server implementing the [Language Server Protocol (LSP)](https://microsoft.github.io/language-server-protocol/) for the object language.

web/README.md

@@ -2,14 +2,19 @@
 
 Based on [tower-lsp-web-demo](https://github.com/silvanshade/tower-lsp-web-demo/), commit `f44085e39430f0f9a9f98e251f67a40a00e3da56`.
 
-## Building
+## Requirements
+
+* [Rust and Cargo](https://www.rust-lang.org/tools/install)
+* [Node.js](https://nodejs.org/en/download) and [npm](https://www.npmjs.com/package/npm)
+
+## Build
 
 ```sh
 make deps
 make build
 ```
 
-## Running
+## Run
 
 ```sh
 make run