static/content: add path to copy button tooltip

Adds the path to the copy button tooltip to
make explicit what is being copied.

Change-Id: Ie2bc1c6832f86351156699bb85b97384e702bb7a
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/260725
Reviewed-by: Julie Qiu <julie@golang.org>
Trust: Jamal Carvalho <jamal@golang.org>
diff --git a/content/static/html/helpers/_unit_fixed_header.tmpl b/content/static/html/helpers/_unit_fixed_header.tmpl
index e63474a..80c8908 100644
--- a/content/static/html/helpers/_unit_fixed_header.tmpl
+++ b/content/static/html/helpers/_unit_fixed_header.tmpl
@@ -22,7 +22,7 @@
         {{with .Breadcrumb}}
           {{if .CopyData}}
             <button class="CopyToClipboardButton js-copyToClipboard"
-                title="Copy path to clipboard"
+                title="Copy path to clipboard.&#10;&#10;{{.CopyData}}"
                 data-to-copy="{{.CopyData}}"
                 tabindex="-1">
               <img class="CopyToClipboardButton-image" src="/static/img/copy-click.svg" alt="">
diff --git a/content/static/html/helpers/_unit_header.tmpl b/content/static/html/helpers/_unit_header.tmpl
index 15076c6..88268a4 100644
--- a/content/static/html/helpers/_unit_header.tmpl
+++ b/content/static/html/helpers/_unit_header.tmpl
@@ -23,7 +23,7 @@
             {{.Current}}
             {{if .CopyData}}
               <button class="CopyToClipboardButton js-copyToClipboard"
-                  title="Copy path to clipboard"
+                  title="Copy path to clipboard.&#10;&#10;{{.CopyData}}"
                   data-to-copy="{{.CopyData}}"
                   tabindex="-1">
                 <img class="CopyToClipboardButton-image" src="/static/img/copy-click.svg" alt="">