Add roadmap link to PDFs page

src/pages/pdfs.md

@@ -28,4 +28,5 @@ Here is the list of PDF links for each of the roadmaps.
 * **Blockchain Roadmap** - [Roadmap Link](https://roadmap.sh/blockchain) / [PDF Link](https://roadmap.sh/pdfs/blockchain.pdf)
 * **Go Roadmap** - [Roadmap Link](https://roadmap.sh/golang) / [PDF Link](https://roadmap.sh/pdfs/go.pdf)
 * **Java Roadmap** - [Roadmap Link](https://roadmap.sh/java) / [PDF Link](https://roadmap.sh/pdfs/java.pdf)
+* **Spring Boot Roadmap** - [Roadmap Link](https://roadmap.sh/spring-boot) / [PDF Link](https://roadmap.sh/pdfs/spring-boot.pdf)
 * **Python Roadmap** - [Roadmap Link](https://roadmap.sh/python) / [PDF Link](https://roadmap.sh/pdfs/python.pdf)