title: how to add a custom configuration settings in the app.config?
body: <p>I have this app.config:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;configuration&gt;
    &lt;configSections&gt;
      &lt;sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"&gt;
        &lt;section name="Me.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /&gt;
        &lt;section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /&gt;
      &lt;/sectionGroup&gt;
  
      &lt;section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /&gt;
    &lt;connectionStrings&gt;
      &lt;add name="MyConnectionString01" connectionString="...." /&gt;
      &lt;add name="MyConnectionString02" connectionString="...." /&gt;
    &lt;/connectionStrings&gt;  
  
    &lt;applicationSettings&gt;
      &lt;Me.Properties.Settings&gt;
        &lt;setting name="BaseDatosMedioAcceso" serializeAs="String"&gt;
          &lt;value&gt;SQLServerEF6&lt;/value&gt;
        &lt;/setting&gt;
      &lt;/Me.Properties.Settings&gt;
    &lt;/applicationSettings&gt;
  
  
    &lt;entityFramework&gt;
      &lt;defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" /&gt;
      &lt;providers&gt;
        &lt;provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" /&gt;
      &lt;/providers&gt;
    &lt;/entityFramework&gt;
  &lt;startup&gt;
  &lt;supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/&gt;&lt;/startup&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>But I would like to add this kind of settings:</p>
  
  <pre><code>&lt;DataBases&gt;
     &lt;add Description="Local" ConnectionString="MyConnectionString01"/&gt;
     &lt;add Description="Local (Test)" ConnectionString="MyConnectionString02"/&gt;
  &lt;/DataBases&gt;
  </code></pre>
  
  <p>But I don't know where tu put this configuration. I have tried to create a config section, but It does not work.</p>
  
  <p>The idea is to have a description that is easy to read for the user and relate this description with the connection string to use with entity framework.</p>
  
  <p>Thanks.</p>