fix example that had .png.jpg in file name, remove character in style guide that's not in the font.

Author: acharraggi

docs/source/contrib/style_guide/image-and-figure-details.rst

@@ -383,7 +383,7 @@ This HTML is from the square field image of the Field Coordinate System page.
    <figure class="align-default" id="id2">
      <img alt="A square field with X, Y and Z axes shown" src="../../_images/image3.jpg">
      <figcaption>
-       <p><span class="caption-text">The Cascade Effect game field</span><a class="headerlink" href="#id2" title="Permalink to this image"></a></p>
+       <p><span class="caption-text">The Cascade Effect game field</span><a class="headerlink" href="#id2" title="Permalink to this image"></a></p>
        <div class="legend">
          <p>In a square field configuration the two Alliances face each other across the field.
          The field is oriented such that the Red Wall is on the right as seen

docs/source/contrib/style_guide/style-guide.rst

@@ -581,7 +581,7 @@ There is a blank line before and after the caption.
 
 .. code:: ReST
 
-   .. figure:: images/into-the-deep-field.png.jpg
+   .. figure:: images/into-the-deep-field.png
       :alt: A square field with X, Y and Z axes shown.
    
       The Into The Deep game field