add translation doc

README.md

@@ -58,10 +58,9 @@ You can find examples in [wgs's repo](https://github.com/fralonra/wgs/tree/maste
 - The amount of the texture you can upload is [the max bind group count of your device](https://docs.rs/wgpu/latest/wgpu/struct.Limits.html#structfield.max_bind_groups) - 1.
 - Won't show any hints on invalid shaders. They just won't compile.
 
-## Todos
+## Contributing
 
-- Web version
-- Advanced shader validation (detailed in https://github.com/fralonra/wgshadertoy/issues/1)
+- [Translations](./i18n/README.md)
 
 ## Credits
 

i18n/README.md

@@ -0,0 +1,19 @@
+# Translations
+
+WgShadertoy uses [Fluent](https://projectfluent.org/) as the localization framework. If you are not familiar with it, we recommend that you read the Fluent documentation first.
+
+## Edit Existing Translation
+
+If you find a translation error (very likely), please help us improve it.
+
+All translation files locate in the [`i18n`](https://github.com/fralonra/wgshadertoy/tree/master/i18n) folder. Please find the corresponding folder according to the [ISO 639 language code](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes), open the `wgshadertoy.ftl` file inside, modify the text, and then submit a PR. Thank you!
+
+## Add A New Language
+
+If you want to add a new language, please create a new folder in the `i18n` folder, named after the [ISO code of the language](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes), copy the [`wgshadertoy.ftl`](https://github.com/fralonra/wgshadertoy/blob/master/i18n/en/wgshadertoy.ftl) file in the `i18n/en` folder to this new folder, and modify it.
+
+Next, you need to find the `LANGUAGES` constant in the [`src/i18n.rs`](https://github.com/fralonra/wgshadertoy/blob/master/src/i18n.rs) file and add the information of the new language properly.
+
+If the new language uses a non-common writing system, the program may not be able to render the text correctly. You should open the [`src/fonts.rs`](https://github.com/fralonra/wgshadertoy/blob/master/src/fonts.rs) file and add the corresponding [writing system](https://en.wikipedia.org/wiki/Script_(Unicode)) and its common fonts in the `FONTS_MAP` constant.
+
+After everything is done, submit a PR. 🍺!

src/fonts.rs

@@ -13,7 +13,7 @@ use std::fs::read;
 // allowing them to load first to reduce the total number of fonts loaded.
 //
 // If you find that a certain language cannot be displayed
-// correctly on your device, please submit feedback: https://github.com/fralonra/wgshadertoy/issues/7”
+// correctly on your device, please submit feedback: https://github.com/fralonra/wgshadertoy/issues/7
 const FONTS_MAP: [(&str, &[&str]); 4] = [
     (
         "Arabic",