Update server-side.mdx (#743)

Fix typo which was breaking link for "File mounts are a powerful way to
run custom files without directly embedding the files in your batch
spec."

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Author: morgangauth

docs/batch-changes/server-side.mdx

@@ -39,7 +39,7 @@ By default, docker on mac will build docker images for `linux/arm64`, which will
 
 <Callout type="note">Running a batch spec server-side with file mounts is currently only supported with [Sourcegraph CLI](https://github.com/sourcegraph/src-cli).</Callout>
 
-File [`mounts`](/batch-changes/batch-spec-yaml-referencee#stepsmount) are a powerful way to run custom files without directly embedding the files in your batch spec.
+File [`mounts`](/batch-changes/batch-spec-yaml-reference#stepsmount) are a powerful way to run custom files without directly embedding the files in your batch spec.
 
 ### Writing a batch spec