feat: Implement trending works feature and add API documentation

This commit introduces a new trending works feature to the application and adds documentation for the new API endpoint.

The feature includes:
- A new `Trending` domain model to store ranked works.
- An `UpdateTrending` method in the `AnalyticsService` that calculates a trending score for each work based on views, likes, and comments.
- A background job that runs hourly to update the trending works.
- A new `trendingWorks` query in the GraphQL API to expose the trending works.
- New tests for the trending feature, and fixes for existing tests.

This commit also includes a refactoring of the analytics repository to use a more generic `IncrementWorkCounter` method, and enhancements to the `WorkStats` and `TranslationStats` models with new metrics like `readingTime`, `complexity`, and `sentiment`.

Finally, this commit adds a new `api/README.md` file with documentation for the `trendingWorks` query.

api/README.md

@@ -0,0 +1,33 @@
+# Tercul API Documentation
+
+This document provides documentation for the Tercul GraphQL API.
+
+## Queries
+
+### `trendingWorks`
+
+The `trendingWorks` query returns a list of trending works.
+
+**Signature:**
+
+```graphql
+trendingWorks(timePeriod: String, limit: Int): [Work!]!
+```
+
+**Arguments:**
+
+*   `timePeriod` (String, optional): The time period to get trending works for. Can be "daily", "weekly", or "monthly". Defaults to "daily".
+*   `limit` (Int, optional): The maximum number of trending works to return. Defaults to 10.
+
+**Example:**
+
+```graphql
+query GetTrendingWorks {
+  trendingWorks(limit: 5) {
+    id
+    name
+  }
+}
+```
+
+This query will return the top 5 trending works for the day.