System.Diagnostics.EventLog: Add README (#78243)

Co-authored-by: carlossanlop <[email protected]>

src/libraries/System.Diagnostics.EventLog/README.md

@@ -0,0 +1,17 @@
+# System.Diagnostics.EventLog
+
+This assembly exposes the System.Diagnostics.EventLog class, which allows the applications to use the Windows event log service.
+
+Documentation can be found at https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.eventlog.
+
+## Contribution Bar
+
+- [x] [We only consider fixes to maintain or improve quality](../README.md#primary-bar)
+- [x] [We consider PRs that target this library for new source code analyzers](../README.md#secondary-bars)
+- [x] [We consider PRs with refactoring changes due to new language features](../README.md#secondary-bars)
+
+See the [Help Wanted](https://github.com/dotnet/runtime/issues?q=is%3Aissue+is%3Aopen+label%3Aarea-System.Diagnostics.EventLog+label%3A%22help+wanted%22) issues.
+
+## Deployment
+
+`System.Diagnostics.EventLog` is provided as a [NuGet package](https://www.nuget.org/packages/System.Diagnostics.EventLog).

src/libraries/System.Diagnostics.EventLog/src/System.Diagnostics.EventLog.csproj

@@ -9,7 +9,7 @@
     <NoWarn>$(NoWarn);CA1845;CA1846</NoWarn>
     <Nullable>annotations</Nullable>
     <IsPackable>true</IsPackable>
-    <PackageDescription>Provides the System.Diagnostics.EventLog class, which allows the applications to use the windows event log service.
+    <PackageDescription>Provides the System.Diagnostics.EventLog class, which allows the applications to use the Windows event log service.
 
 Commonly Used Types:
 System.Diagnostics.EventLog</PackageDescription>