docs: update README for clarity

- Updated download instructions with new link and asset details
- Updated example command to match new JAR naming convention
- Added new "API" section for integration guidance
- Linked Maven dependency and example `Main.java`

Signed-off-by: Minecon724 <git@m724.eu>

README.md

@@ -2,14 +2,21 @@ blog-software(config, template, content) = blog website
 
 ## Usage
 
-1. [Download the program](https://git.m724.eu/Minecon724/blog-software-java/actions/runs/latest/artifacts/built-jar)
+1. [Download the program from here](https://git.m724.eu/Minecon724/-/packages/maven/eu.m724-blog) \
+   Locate "Assets" and download the **-shaded**.jar
 2. Get a working directory. [Example](https://git.m724.eu/Minecon724/blog-software-java/src/branch/master/example_workdir) \
    Don't forget to `git init`!
 3. Run the program:
    ```shell
-    java -jar blog-software-java-1.0-SNAPSHOT.jar
+    java -jar blog-0.0.1-shaded.jar
     ```
    
 ## Important caveats
 Generated site must be the root of a subdomain, like `https://example.com/`. \
 You can't put it in a directory, like `https://example.com/blog/`
+
+## API
+There's no "API," but it's possible to integrate this into your Java project.
+
+See [Main.java](/Minecon724/blog-software-java/src/branch/master/src/main/java/eu/m724/blog/Main.java) for an example. \
+If you need a Maven dependency, [see here](https://git.m724.eu/Minecon724/-/packages/maven/eu.m724-blog)