update readme

README.md

@@ -1,14 +1,93 @@
 # Donkeytype
 
-very minimalistic **_cli_** typing test
+a _very_ minimalistic _cli_ typing test.
 
 ### Todo
 
+-   [ ] docs
+-   [ ] add CONTRIBUTING.md
+-   [ ] save results to csv
+-   [ ] read results from csv and display them
+-   [ ] deployment to homebrew?
 -   [ ] count wpm only in words that were typed correctly
--   [ ] save results
 -   [ ] handle alt+backspace to delete last word from input
--   [ ] support numbers and symbols
+-   [ ] support uppercase letters at the beginning of words
+-   [ ] support numbers
+-   [ ] support symbols
+-   [ ] support configuring color scheme
 -   [ ] figure out a way to mock tui::widgets::Widget to test if expected text is rendered
--   [ ] add support for more languages
 -   [ ] handle unicode characters (e.g. `ł`, `ń`, `ü`, `ß`)
+-   [ ] add support for more languages
 -   [ ] add integration tests
+
+## How it works
+
+When run the program you will see the expected input displayed at the top of your terminal window.
+This text is a placeholder, and this is the input that you should write when the test is started.
+
+On the bottom-right corner there is a help message saying that to start the test you need to press `'e'` (enter the test) or leave by pressing `'q'`
+When test is running you can see how much time you have left in bottom-left corner.
+
+You can pause the test by pressinng <Esc>, to resume it press `'e'` again.
+
+WPM (words per minute) is calculated as amount of typed characters divided by 5 (word), divided by the duration normalized to 60 seconds (minute).
+
+## Usage
+
+### Installation
+
+For now there is now deployment environment setup.
+You can clone the repo, and run the main program with cargo:
+
+```shell
+cargo run
+```
+
+To start the program with default config.
+
+### Configuring
+
+For now there are only two options that are read from config.
+Configuration will grow when more features are added (different modes, different languages, configuring colors).
+
+Default config looks like this:
+
+| name            | default value        | type in JSON | description                                                          |
+| --------------- | -------------------- | ------------ | -------------------------------------------------------------------- |
+| duration        | 30                   | number       | duration of the test in seconds                                      |
+| dictionary_path | "src/dict/words.txt" | string       | dictionary words to sample from while creating test's expected input |
+
+You can provide this config as options when running the program like so:
+
+```shell
+cargo run -- --duration 60
+```
+
+or put them in a config file in `~/.config/donkeytype/donkeytype-config.json`:
+
+```json
+{
+    "duration": 60
+}
+```
+
+To get all the available options run
+
+```shell
+cargo run -- --help
+```
+
+## Development
+
+### Prerequisites
+
+You need to have [rust](https://www.rust-lang.org/) installed to run & develop this program locally.
+
+## Contributing
+
+See [CONTRIBUTING.md](CONTRIBUTING.md)
+
+## License
+
+MIT.
+See [LICENSE](./LICENSE)