MNT: set dflt and min values of lw inputs to 0

Since we're moving to having line width be explicitly in
understandable units of "extra width around the line," 0 will be the
baseline

empress/support_files/templates/side-panel.html

@@ -38,7 +38,7 @@
       </p>
       <p>
         <label for="sample-line-width">Line Width</label>
-        <input id="sample-line-width" type="number" value="1" min="1">
+        <input id="sample-line-width" type="number" value="0" min="0">
       </p>
       <p>
         <button id="sample-update" class="hidden">Update</button>
@@ -72,7 +72,7 @@
       </p>
       <p>
         <label for="feature-line-width">Line Width</label>
-        <input id="feature-line-width" type="number" value="1" min="1">
+        <input id="feature-line-width" type="number" value="0" min="0">
       </p>
       <p>
         <label for="fm-method-chk">Only use tip-level metadata?</label>
@@ -133,7 +133,7 @@
   </p>
   <p>
     <label for="animate-line-width">Line Width</label>
-    <input id="animate-line-width" type="number" value="1" min="1">
+    <input id="animate-line-width" type="number" value="0" min="0">
   </p>
   <div>
     <p>