prepare for logo prefixes here as well.

docs/make.jl

@@ -60,7 +60,7 @@ makedocs(;
     # for development, we disable prettyurls
     format = Documenter.HTML(;
         prettyurls = (get(ENV, "CI", nothing) == "true") || ("--prettyurls" ∈ ARGS),
-        assets = ["assets/favicon.ico", "assets/citations.css"],
+        assets = ["assets/favicon.ico", "assets/citations.css", "assets/link-icons.css"],
         size_threshold_warn = 200 * 2^10, # raise slightly from 100 to 200 KiB
         size_threshold = 300 * 2^10,      # raise slightly 200 to to 300 KiB
     ),

docs/src/assets/link-icons.css

@@ -0,0 +1,41 @@
+a[href^="https://juliamanifolds.github.io/Manifolds.jl/"]::before {
+    content: "";
+    background-image: url('logo-manifolds.png');
+    background-size: contain;
+    background-repeat: no-repeat;
+    display: inline-block;
+    height: 1em;
+    width: 1em;
+    margin-right: 4px;
+    vertical-align: middle;
+}
+
+a[href^="https://manoptjl.org/"]::before {
+    content: "";
+    background-image: url('logo-manopt.png');
+    background-size: contain;
+    background-repeat: no-repeat;
+    display: inline-block;
+    height: 1em;
+    width: 1em;
+    margin-right: 4px;
+    vertical-align: middle;
+}
+
+a[href^="https://en.wikipedia.org/"]::before {
+    content: "";
+    background-image: url('wikipedia.png');
+    background-size: contain;
+    background-repeat: no-repeat;
+    display: inline-block;
+    height: 1em;
+    width: 1em;
+    margin-right: 4px;
+    vertical-align: middle;
+}
+
+@media (prefers-color-scheme: dark) {
+    a[href^="https://juliamanifolds.github.io/Manifolds.jl/"]::before {
+        background-image: url('logo-manifolds-dark.png');
+    }
+}