fixed the grammatical error

Author: praveenkuttappan

eng/common/instructions/azsdk-tools/typespec-to-sdk.instructions.md

@@ -23,7 +23,7 @@ As a first step, you must prompt the user to understand the intention of SDK gen
 Generate SDK locally in cases below:
 - If the user wants to walk through each SDK generation step locally. This approach requires user to have the setup for each language to generate SDK locally. User can create a pull request for each language after completing all the steps in SDK generation successfully to get the generated SDK reviewed and merged.
 - If the user wants to troubleshoot a failed SDK generation by the pipeline.
-- If SDK or client.tsp customization are needed before creating a pull request.
+- If SDK or client.tsp customizations are needed before creating a pull request.
 
 Generate SDK using pipeline:
 - If the user wants to generate SDK and get a PR automatically created in Azure SDK language repositories. This approach can be followed if the user does not want to setup local environment for each language.