Tweak length and sizing of API source links

This ensures that this link has ample space around it for `.headerlink`
elements.

src/furo/_demo_module.py

@@ -51,3 +51,17 @@ def get_random_integer(self) -> int:
     def get_random_float(self) -> float:
         """Return a random float."""
         return float(self.seed)
+
+
+def annoying_function_name_length_aa(one: int, two: int) -> str:
+    """A function that adds two numbers as strings.
+
+    Because I needed a placeholder function."""
+    return str(one) + str(two)
+
+
+def annoying_function_name_length_aaa(one: int, two: int) -> str:
+    """A function that adds two numbers as strings.
+
+    Because I needed a placeholder function."""
+    return str(one) + str(two)

src/furo/assets/styles/content/_api.sass

@@ -66,7 +66,7 @@ dl[class]:not(.option-list):not(.field-list):not(.footnote):not(.glossary):not(.
   a.reference
     .viewcode-link
       font-weight: normal
-      width: 3.5rem
+      width: 4.25rem
 
 em.property
   font-style: normal