Fixed image caption design bugs in Koenig

no refs.
- added side padding for alt and caption input fields
- fixed text color bug of alt toggle button

lib/koenig-editor/addon/components/koenig-alt-input.hbs

@@ -1,7 +1,7 @@
 <input
     type="text"
     placeholder={{this.placeholder}}
-    class="miw-100 tc bn form-text bg-transparent tracked-2"
+    class="miw-100 tc bn form-text bg-transparent tracked-2 pr8 pl8"
     name="alt"
     value={{this.alt}}
     {{on "input" this.onInput}}

lib/koenig-editor/addon/components/koenig-caption-input.hbs

@@ -1,7 +1,7 @@
 <KoenigBasicHtmlInput
     @html={{this.caption}}
     @placeholder={{if this.isFocused "" this.placeholder}}
-    @class="miw-100 tc bn form-text bg-transparent"
+    @class="miw-100 tc bn form-text bg-transparent pr8 pl8"
     @name="caption"
     @onChange={{action this.update}}
     @onFocus={{action (mut this.isFocused) true}}

lib/koenig-editor/addon/components/koenig-card-image.hbs

@@ -80,7 +80,7 @@
         {{#if this.isSelected}}
             <button
                 title="Toggle between editing alt text and caption"
-                class="absolute right-0 bottom-0 ma2 pl1 pr1 ba br3 f8 sans-serif fw4 lh-title tracked-2 {{if this.isEditingAlt "bg-blue b--blue blue" "bg-white b--midlightgrey midlightgrey"}}"
+                class="absolute right-0 bottom-0 ma2 pl1 pr1 ba br3 f8 sans-serif fw4 lh-title tracked-2 {{if this.isEditingAlt "bg-blue b--blue white" "bg-white b--midlightgrey midlightgrey"}}"
                 {{on "click" this.toggleAltEditing passive=true}}
             >
                 Alt