Update README.md

Signed-off-by: Manos Pitsidianakis <[email protected]>

README.md

@@ -1,10 +1,16 @@
 # `rlr`: a pixel screen ruler
 
+![Minimum Supported Rust Version](https://img.shields.io/badge/MSRV-1.70.0-blue) [![GitHub license](https://img.shields.io/github/license/epilys/rlr)](https://github.com/epilys/rlr/blob/master/LICENSE) [![Crates.io](https://img.shields.io/crates/v/rlr-gtk)](https://crates.io/crates/rlr-gtk)
+
 ![./rlr.png](./rlr.png)
 
 Rust + GTK interactive pixel screen ruler with protractor mode.
 
-## demo
+```shell
+cargo install rlr
+```
+
+## Demo
 
 <table>
 <tr><td colspan=2 align="center"><kbd>
@@ -20,27 +26,54 @@ Rust + GTK interactive pixel screen ruler with protractor mode.
 
 </kbd></td></tr></table>
 
+## Use
+
+To use application settings, the app's settings schema but be installed in your system.
+It is possible to attempt to do this automatically via the Settings menu, which will install the schema to `${HOME}/.local/share/glib-2.0/schemas/` and subsequently attempt to compile it; but the directory must exist beforehand, it won't be created.
+
+`rlr` includes a command-line argument `--install-gsettings-schema` that creates the settings schema at the given directory.
+If directory is `-`, it will be printed to standard output instead.
+
+*Note*: The directory values should probably be one of: `${HOME}/.local/share/glib-2.0/schemas/`, `/usr/share/glib-2.0/schemas/` or similar.
+
+For the settings schema to be discoverable, it must be compiled with `glib-compile-schemas`.
+
+An example usage:
+
+```shell
+rlr --install-gsettings-schema "${HOME}/.local/share/glib-2.0/schemas/"
+```
+
+and then:
+
+```shell
+glib-compile-schemas "${HOME}/.local/share/glib-2.0/schemas/"
+```
+
+### Shortcuts
 
-## use
+If you are on macOS, use <kbd>⌘</kbd> (Command) key instead of <kbd>Ctrl</kbd>.
 
-- Quit with `q` or `Ctrl-Q`.
-- Click to drag.
-- Press `r` to rotate 90 degrees. Press `<Shift>r` to flip (mirror) the marks without rotation.
-- Press `p` to toggle protractor mode.
-- Press `f` or `<Space>` to toggle freezing the measurements.
-- Press `Control_L` and drag the angle base side to rotate it in protractor mode.
-- Press `Control_L` continuously to disable precision (measurements will snap to nearest integer).
-- Press `+` to increase size.
-- Press `-` to decrease size.
-- Press `Up`, `Down`, `Left`, `Right` to move window position by 10 pixels. Also hold down `Control_L` to move by 1 pixel.
+- **Quit** with <kbd>q</kbd> or <kbd>Ctrl</kbd> + <kbd>Q</kbd>.
+- Click to **drag**.
+- Press <kbd>?</kbd> or <kbd>F1</kbd> to **open the About and Help window**.
+- Press <kbd>s</kbd> or <kbd>F2</kbd> to **open the Settings window**.
+- Press <kbd>r</kbd> to **rotate** 90 degrees. Press <kbd>Shift</kbd> + <kbd>r</kbd> to **flip (mirror)** the marks without rotation.
+- Press <kbd>p</kbd> to toggle **protractor mode**.
+- Press <kbd>f</kbd> or <kbd>Space</kbd> to toggle **freezing the measurements**.
+- Press <kbd>Ctrl</kbd> and drag the angle base side to **rotate it while in protractor mode**.
+- Press <kbd>Ctrl</kbd> continuously to **disable precision** (measurements will snap to nearest integer).
+- Press <kbd>+</kbd> to **increase size**. Press <kbd>-</kbd> to **decrease size**.
+- Press <kbd>Ctrl</kbd> + <kbd>+</kbd>, <kbd>Ctrl</kbd> + <kbd>+</kbd> to **increase font size**. Press <kbd>Ctrl</kbd> + <kbd>-</kbd>, <kbd>Ctrl</kbd> + <kbd>-</kbd> to **decrease font size**.
+- Press <kbd>Up</kbd>, <kbd>Down</kbd>, <kbd>Left</kbd>, <kbd>Right</kbd> to **move window position by 10 pixels**. Also hold down <kbd>Ctrl</kbd> to **move by 1 pixel**.
 
-## build
+## Build
 
 ```shell
 cargo build --release
 ```
 
-## packaging
+## Packaging
 
 To help packagers in OSes that support the XDG Desktop standards, a `.desktop`
 app launcher filer, an application icon and a symbolic application icon are

src/main.rs

@@ -1838,6 +1838,7 @@ fn show_about_window(window: &gtk::ApplicationWindow) {
         format!(
             "{bs}Quit{be} with {ms}q{me} or {ms}{lt}{primary}{gt}Q{me}.
 Click to {bs}drag{be}.
+Press {ms}?{me} or {ms}F1{me} to {bs}open the About and Help window{be}.
 Press {ms}s{me} or {ms}F2{me} to {bs}open the Settings window{be}.
 Press {ms}r{me} to {bs}rotate{be} 90 degrees. Press {ms}{lt}Shift{gt}r{me} to {bs}flip \
              (mirror){be} the marks without rotation.