Update Other section with example exit code

Add troubleshooting steps to remediate issues with the kernel killing a process.

Author: securingdev

docs/codeql/codeql-cli/exit-codes.rst

@@ -71,4 +71,4 @@ Other
 -----
 
 In the case of really severe problems within the JVM that runs ``codeql``, it might return a nonzero exit code of its own choosing.
-This should only happen if something is severely wrong with the CodeQL installation.
+This should only happen if something is severely wrong with the CodeQL installation, or a memory issue with the host system running the CodeQL process. For example, Unix systems may return `Exit Code 137` to indicate that the kernel has killed a process that CodeQL has started. One way to troubleshoot this issue is to modify your `--ram=` flag for the `codeql database analyze` step and re-run your workflow.