marketplace: replace keyword "AWS" with "Lambda"

Problem:
We don't need "AWS" as a keyword because it is in the extension title
"AWS Toolkit". VS marketplace limits us to 5 keywords.

Solution:
Replace keyword "AWS" with "Lambda".

Author: justinmk3

package.json

@@ -29,7 +29,7 @@
         "Other"
     ],
     "keywords": [
-        "AWS",
+        "Lambda",
         "CodeCatalyst",
         "CodeWhisperer",
         "Code",