Update Readme.md (#39487)

Fix type in /src/analyzers/readme.md
#39481

src/Analyzers/Readme.md

@@ -1,6 +1,6 @@
 # Analyzers
 
-This directory contains sources for analyers used internally by ASP.NET Core.
+This directory contains sources for analyzers used internally by ASP.NET Core.
 
 ## Description