Add docs

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unreleased
 
-* Ability to load a Context from a dotenv file
+* Add support for loading the context's environment from a dotenv file
 
 ## 0.5.1 (2023-06-22)
 

doc/05-context.md

@@ -118,3 +118,24 @@ function foo(Context $context): void
     run('pwd'); // will print /tmp
 }
 ```
+
+## Load a context from dotenv file
+
+You can also load your context from a dotenv file:
+
+```php
+use Castor\Attribute\AsContext;
+use Castor\Context;
+
+#[AsContext]
+function my_context(): Context
+{
+    return new Context::fromDotEnv();
+}
+```
+
+By default, it loads the `.env` file on your project root (where castor file or
+folder was found), but you can overload this by passing your dotenv file
+path as an argument.
+You can find more about how dotenv file loading and overloading works on 
+[related Symfony documentation](https://symfony.com/doc/current/configuration.html#configuring-environment-variables-in-env-files).