missing 'a'

Author: nathan-websculpt

website/src/pages/en/subgraphs/developing/creating/unit-testing-framework.mdx

@@ -1291,7 +1291,7 @@ test('file/ipfs dataSource creation example', () => {
 
 Using **Matchstick**, Subgraph developers are able to run a script that will calculate the test coverage of the written unit tests.
 
-The test coverage tool takes the compiled test `wasm` binaries and converts them to `wat` files, which can then be easily inspected to see whether or not the handlers defined in `subgraph.yaml` have been called. Since code coverage (and testing as whole) is in very early stages in AssemblyScript and WebAssembly, **Matchstick** cannot check for branch coverage. Instead we rely on the assertion that if a given handler has been called, the event/function for it have been properly mocked.
+The test coverage tool takes the compiled test `wasm` binaries and converts them to `wat` files, which can then be easily inspected to see whether or not the handlers defined in `subgraph.yaml` have been called. Since code coverage (and testing as a whole) is in very early stages in AssemblyScript and WebAssembly, **Matchstick** cannot check for branch coverage. Instead we rely on the assertion that if a given handler has been called, the event/function for it have been properly mocked.
 
 ### Prerequisites