title: Localization with String interpolation in SwiftUI
body: <p>I am trying to localize my SwiftUI Watch app.
  I don't have any problems with static strings. I use LocalizedKeyStrings in my Text views and add my translations in Localizable.strings files.
  For example:</p>
  
  <pre><code>Text("history")
  </code></pre>
  
  <p>in Localizable.strings:</p>
  
  <pre><code>"history" = "Historique";
  </code></pre>
  
  <p>Result : 
  "Historique"</p>
  
  <p>But I also want to localize stings using interpolation. For example:</p>
  
  <pre><code>Text("startCustom \(format: "%.1f",customDistance)")
  </code></pre>
  
  <p>In Localizable.strings, I have tried with different syntax:</p>
  
  <pre><code>"startCustom %@" = "Course de %@ km";
  </code></pre>
  
  <p>or</p>
  
  <pre><code>"startCustom %f" = "Course de %f km";
  </code></pre>
  
  <p>or</p>
  
  <pre><code>"startCustom %.1f" = "Course de %.1f km";
  </code></pre>
  
  <p>Nothing works.
  I don't find any documentation for that ...</p>