Make filenames fuzzy-searchable

I don't want a bunch of files coming up when I fuzzy search for "index".
Make it so using the same name within a folder equates to creating the
index for that folder.

lib/build_paths.rb

@@ -6,10 +6,16 @@ def source_path
   end
 
   def target_path
-    path
-      .sub(Build.source_dir, Build.target_dir)
-      .sub(".md", "/index.html")
-      .sub("/index/index.html", "/index.html")
+    extname = File.extname(path)
+    segments =
+      path
+        .sub(Build.source_dir, Build.target_dir)
+        .delete_suffix(extname)
+        .split("/")
+    segments.pop if segments.last(2).uniq.size == 1
+    segments.pop if segments.last == "index"
+    segments.push("index.html")
+    segments.join("/")
   end
 
   def url

test/build_paths_test.rb

@@ -16,4 +16,15 @@ def test_non_index_markdown_path
     assert_equal("_site/path/to/another-thing/index.html", dummy.target_path)
     assert_equal("/path/to/another-thing/", dummy.url)
   end
+
+  def test_duplicate_identifier_path
+    dummy = Dummy.new("site/path/to/another-thing/another-thing.md")
+    assert_equal("site/path/to/another-thing/another-thing.md", dummy.path)
+    assert_equal(
+      "site/path/to/another-thing/another-thing.md",
+      dummy.source_path
+    )
+    assert_equal("_site/path/to/another-thing/index.html", dummy.target_path)
+    assert_equal("/path/to/another-thing/", dummy.url)
+  end
 end