doc: fix wrong link to server in contributing.md (#427)

* doc: fix wrong link to server in contributing.md

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Co-authored-by: jimsu <jimsu@protonmail.com>

CONTRIBUTING.md

@@ -76,7 +76,12 @@ As described in [here](https://github.com/OpenDevin/OpenDevin/labels), we create
 
 
 ## How to begin
-Please check the details in each parts: [frontend](./frontend/README.md), [agenthub](./agenthub/README.md), [evaluation](./evaluation/README.md), [server](./server/README.md).
+Please refer to the README in each module:
+- [frontend](./frontend/README.md)
+- [agenthub](./agenthub/README.md)
+- [evaluation](./evaluation/README.md)
+- [opendevin](./opendevin/README.md)
+    - [server](./opendevin/server/README.md)
 
 ## Tests
 TODO: make sure code pass the test before submit.