Add comments regarding HSTS max age

Commit migrated from dotnet/aspnetcore@11c6ebea2e

src/Microsoft.DotNet.Web.Spa.ProjectTemplates/content/Angular-CSharp/Startup.cs

@@ -42,6 +42,7 @@ namespace Company.WebApplication1
             {
                 app.UseExceptionHandler("/Error");
 #if (!NoHttps)
+                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                 app.UseHsts();
             }
 

src/Microsoft.DotNet.Web.Spa.ProjectTemplates/content/React-CSharp/Startup.cs

@@ -42,6 +42,7 @@ namespace Company.WebApplication1
             {
                 app.UseExceptionHandler("/Error");
 #if (!NoHttps)
+                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                 app.UseHsts();
             }
 

src/Microsoft.DotNet.Web.Spa.ProjectTemplates/content/ReactRedux-CSharp/Startup.cs

@@ -42,6 +42,7 @@ namespace Company.WebApplication1
             {
                 app.UseExceptionHandler("/Error");
 #if (!NoHttps)
+                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                 app.UseHsts();
             }