Wikipedia: tweak EPUB css and footnote styletweaks

EPUB: have pages with footnotes marked as non-linear
so they can be hidden with "Hide non-linear flows".
In-page footnotes: keep the footnote number near the
left margin (a recent crengine renders them near the
text by default).

frontend/ui/data/css_tweaks.lua

@@ -834,6 +834,7 @@ This only works with footnotes that have specific attributes set by the publishe
                 css = [[
 ol.references > li {
     -cr-hint: footnote-inpage;
+    list-style-position: -cr-outside;
     margin: 0 !important;
 }
 /* hide backlinks */
@@ -848,6 +849,7 @@ ol.references > li > .mw-cite-backlink { display: none; }
                 css = [[
 ol.references > li {
     -cr-hint: footnote-inpage;
+    list-style-position: -cr-outside;
     margin: 0 !important;
     font-size: 0.8rem !important;
 }

frontend/ui/wikipedia.lua

@@ -956,6 +956,8 @@ body {
 }
 ol.references {
     list-style-type: inherit;
+    /* Allow hiding these pages as their content is available as footnotes */
+    -cr-hint: non-linear;
 }
 
 /* Show a box around image thumbnails */