title: Injecting parameters and HTML into ngx-translate key
body: <p>Is this possible? Say I have the following text I want to translate:</p>
  
  <pre><code>&lt;p&gt;You currently have &lt;span class="bold"&gt;{{rewards?.points}}&lt;/span&gt; points worth &lt;span class="bold"&gt;{{rewards?.amount | currency}}&lt;/span&gt; statement credit.&lt;/p&gt;
  </code></pre>
  
  <p>I want this text to be translatable but two things are tripping me up - how to inject variables number of points/amount and how to preserve the bolded span tag. </p>
  
  <p>From my en-US.json file:</p>
  
  <pre><code>"statement": "You currently have {{points_param}} points worth {{credit_param}} statement credit."
  </code></pre>
  
  <p>Doing the following works if I want to use a static value for the points/amount, but that doesn't preserve the bold styling or allow for a variable value.</p>
  
  <pre><code>&lt;p [innerHTML]="'redeem.statement' | translate:{points_param:'50',credit_param:'100'}"&gt;&lt;/p&gt;
  </code></pre>