add route template docs

docs/RouteTemplate.md

@@ -0,0 +1,73 @@
+# Route templating
+
+The library contains functionality for route templating which allows you to provide
+the arguments to your api calls at runtime while defining the routes beforehand using
+variable placeholders.
+
+**Example config:**
+
+
+```js
+const apiRouter = createRouter({
+    cats: '/cats', // Static route
+    cat: '/cats/${pk}', // Dynamic route with a placeholder
+    children: {
+        cats: '/cats/children/${cat.pk}/${cat.child.pk}', // Nested property placeholder
+        dogs: '/dogs/children/${cat.pk}/{dog.child.pk}'  // Alternative placeholder syntax
+    },
+}, {
+    apiRoot: '/api/v1',
+}, Resource);
+```
+
+## Calling a route
+
+To call a route, provide an object with values to replace the placeholders. The library dynamically replaces the placeholders with corresponding values from the kwargs object.
+
+```js
+// Fetches from "/api/v1/cats"
+const route = apiRouter.cats.fetch();
+
+// Fetches from "/api/v1/cats/123"
+const dynamicRoute = apiRouter.cat.fetch({ pk: 123 }); 
+
+// Fetches from "/api/v1/cats/children/1/456"
+const nestedRoute = apiRouter.children.cats.fetch({ cat: { pk: 1, child: { pk: 456 } } });
+
+// Fetches from "/api/v1/dogs/children/2/789"
+const anotherNestedRoute = apiRouter.children.dogs.fetch({ dog: { pk: 2, child: { pk: 789 } } });
+```
+
+## Nested Values
+
+The library supports nested objects. Use the . separator to reference nested properties in your placeholders.
+
+```js
+// in route path
+> '/cats/children/${cat.pk}/${cat.child.pk}'
+// with kwargs: `{ cat: { pk: 1, child: { pk: 456 } } }`
+> '/api/v1/cats/children/1/456'
+```
+
+## Placeholder Syntax
+
+You can use either of the following placeholder syntaxes in your route templates:
+
+1. Template Literal Syntax (`${}`):
+   - Example: `/cats/${pk}`
+2. Curly Braces Syntax (`{}`):
+   - Example: `/dogs/{pk}`
+
+Both syntaxes work interchangeably.
+
+## Missing values in kwargs
+
+If a value provided in the template is missing, it just gets removed from the url. For example:
+
+
+```js
+// in route path
+> '/cats/children/${cat.pk}/'
+// with kwargs: `{}` or `null`
+> '/api/v1/cats/children/1/'
+```

docs/_sidebar.md

@@ -1,3 +1,3 @@
 
 * [General](/)
-<!-- * [Error Handling](ErrorHandling.md) -->
+* [Route templates](RouteTemplate.md)