Add docs to releases table

Author: szarnyasg

README.md

@@ -17,6 +17,7 @@ To ensure that you are using compatible LDBC repositories, use the following tab
 
 | project | v0.3.x | v0.4.x |
 | ------- | ------ | ------ |
+| [Documentation](https://github.com/ldbc/ldbc_snb_docs) | [`v0.3.3`](https://github.com/ldbc/ldbc_snb_docs/releases/tag/v0.3.3) | [`dev`](https://github.com/ldbc/ldbc_snb_docs/tree/dev) |
 | [Datagen](https://github.com/ldbc/ldbc_snb_datagen) | [`v0.3.3`](https://github.com/ldbc/ldbc_snb_datagen/releases/tag/v0.3.3) | [`dev`](https://github.com/ldbc/ldbc_snb_datagen/tree/dev) |
 | [Driver](https://github.com/ldbc/ldbc_snb_driver) | [`v0.3.3`](https://github.com/ldbc/ldbc_snb_driver/releases/tag/0.3.3) | [`dev`](https://github.com/ldbc/ldbc_snb_driver/tree/dev) |
 | [Implementations](https://github.com/ldbc/ldbc_snb_implementations) | [`stable`](https://github.com/ldbc/ldbc_snb_implementations/tree/stable) | [`dev`](https://github.com/ldbc/ldbc_snb_implementations/tree/dev) |