Created SC2130 (markdown)

SC2130.md

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+## -eq is for integer comparisons. Use = instead.
+
+### Problematic code:
+
+    [[ $foo -eq "Y" ]]
+
+### Correct code:
+
+    [[ $foo = "Y" ]]
+
+### Rationale:
+
+Shells have two sets of comparison operators: for integers (`-eq`, `-gt`, ...) and strings (`=`, `>`, ...). ShellCheck has noticed that you're using an integer comparison with string data.
+
+If you are in fact comparing integers, double check your parameters. Certain mistakes like `$$foo` or `${bar}}` can introduce non-numeric characters into otherwise numeric arguments.
+
+### Contraindications
+
+None.