Rollup merge of #92602 - jsha:source-link-2, r=GuillaumeGomez

Make source links look cleaner

Change from syntaxy-looking [src] to the plain word "source".

Change the syntaxy-looking `[-]` at the top of the page to say "collapse".

Reduce opacity of rightside content.

Part of #59851

r? `@GuillaumeGomez`

Demo: https://rustdoc.crud.net/jsha/source-link-2/std/string/struct.String.html

[Discussed on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/266220-rustdoc/topic/display.20of.20source.20link).

src/librustdoc/html/render/mod.rs

@@ -182,7 +182,7 @@ impl StylePath {
 
 fn write_srclink(cx: &Context<'_>, item: &clean::Item, buf: &mut Buffer) {
     if let Some(l) = cx.src_href(item) {
-        write!(buf, "<a class=\"srclink\" href=\"{}\" title=\"goto source code\">[src]</a>", l)
+        write!(buf, "<a class=\"srclink\" href=\"{}\" title=\"goto source code\">source</a>", l)
     }
 }
 
@@ -799,7 +799,7 @@ fn render_stability_since_raw(
     const_stability: Option<ConstStability>,
     containing_ver: Option<Symbol>,
     containing_const_ver: Option<Symbol>,
-) {
+) -> bool {
     let ver = ver.filter(|inner| !inner.is_empty());
 
     match (ver, const_stability) {
@@ -842,8 +842,9 @@ fn render_stability_since_raw(
                 v
             );
         }
-        _ => {}
+        _ => return false,
     }
+    true
 }
 
 fn render_assoc_item(
@@ -1632,7 +1633,7 @@ fn render_impl(
 }
 
 // Render the items that appear on the right side of methods, impls, and
-// associated types. For example "1.0.0 (const: 1.39.0) [src]".
+// associated types. For example "1.0.0 (const: 1.39.0) · source".
 fn render_rightside(
     w: &mut Buffer,
     cx: &Context<'_>,
@@ -1650,13 +1651,16 @@ fn render_rightside(
     };
 
     write!(w, "<div class=\"rightside\">");
-    render_stability_since_raw(
+    let has_stability = render_stability_since_raw(
         w,
         item.stable_since(tcx),
         const_stability,
         containing_item.stable_since(tcx),
         const_stable_since,
     );
+    if has_stability {
+        w.write_str(" · ");
+    }
 
     write_srclink(cx, item, w);
     w.write_str("</div>");