docs(options): Improve docs for options.

Author: ryasmi

docs/options.md

@@ -2,29 +2,50 @@
 
 The [facade](./facade.md) [functions](./functions.md) have some common options that they use.
 
-- [Entity](#entity)
 - [Id](#id)
+- [Entity](#entity)
 - [Patch](#patch)
 - [Filter](#filter)
 - [Sort](#sort)
 - [Pagination](#pagination)
 
+### Id
+This is an object that contains only the properties required to distinctly identify an entity. In most common cases there is a single property making the [unique key](https://en.wikipedia.org/wiki/Unique_key) so it will likely just contain the `id` property. However, for entities with multiple properties making the unique key it will contain those properties.
+
+This interface is user-defined hence not contained in this package, the interface below demonstrates what this will look like in most cases.
+
+```ts
+interface Id {
+  readonly id: string;
+}
+```
+
 ### Entity
 This is an object contains all of the entity's properties. The word "entity" has been borrowed from Entity-Relationship Models/Diagrams and has been used instead of the word "model" to avoid confusion with MVC.
 
-### Id
-This is an object that contains only the properties required to distinctly identify an entity. In most common cases there is a single property making the [unique key](https://en.wikipedia.org/wiki/Unique_key) so it will likely just contain the `id` property. However, for entities with multiple properties making the unique key it will contain those properties.
+This interface is user-defined hence not contained in this package, the interface below demonstrates what this might look like for a todo entity and extends the [Id interface from the Id example](#id).
+
+```ts
+interface TodoEntity extends Id {
+  readonly description: string;
+  readonly completed: boolean;
+}
+```
 
 ### Patch
-This is an object containing some of the entity's properties.
+This is an object containing some of the entity's properties. This package uses [TypeScript's Partial type](https://www.typescriptlang.org/docs/handbook/advanced-types.html) applied to an [Entity](#entity) (using `Partial<Entity>`).
 
 ### Filter
 This is an object that filters the entities. More information can be found in the [filter documentation](./filter.md).
 
 ### Sort
 This is an object where a key represents the entity property to be sorted and the value represents the direction to sort. The value should be `true` to sort in ascending order and `false` to sort in descending order. The properties are sorted in order of their definition in the sort option, for example, the following sort option `{ createdAt: false, id: true }` will sort by the `createdAt` property first and then the the `id` property.
 
+This package contains the [TypeScript Sort type definition](../src/types/Sort.ts)
+
 ### Pagination
 This is an object with three properties, `limit`, `forward`, and `cursor`. The `limit` property defines how many entities to return (maximum). The `forward` property defines whether the entities should be iterate through the entities forwards (when `true`) or backwards (when `false`) from the `cursor`. The `cursor` property defines where to start iterating through the entities.
 
-Concrete implementations of the facade can use the [`createCursorFromEntity`](../src/utils/createCursorFromEntity) and [`createPaginationFilter`](../src/utils/createPaginationFilter) util functions to generate cursors.
+Concrete implementations of the facade can use the [`createCursorFromEntity`](../src/utils/createCursorFromEntity) and [`createPaginationFilter`](../src/utils/createPaginationFilter) util functions to generate cursors.
+
+This package also contains the [TypeScript Pagination interface](../src/types/Pagination.ts) and the [TypeScript Cursor type definition](../src/types/Cursor.ts).