BUGFIX: Coding contracts may have duplicate names (#2399)

markdown/bitburner.codingcontract.createdummycontract.md

@@ -9,7 +9,7 @@ Generate a dummy contract.
 **Signature:**
 
 ```typescript
-createDummyContract(type: CodingContractName): string;
+createDummyContract(type: CodingContractName): string | null;
 ```
 
 ## Parameters
@@ -50,7 +50,7 @@ Type of contract to generate
 
 **Returns:**
 
-string
+string \| null
 
 Filename of the contract.
 
@@ -60,3 +60,5 @@ RAM cost: 2 GB
 
 Generate a dummy contract on the home computer with no reward. Used to test various algorithms.
 
+This function will return null and not generate a contract if the randomized contract name is the same as another contract's name.
+