docs/lib: use note/warning markup more consistently

lib/attrsets.nix

@@ -715,10 +715,10 @@ rec {
     Iterates over every name-value pair in the given attribute set.
     The result of the callback function is often called `acc` for accumulator. It is passed between callbacks from left to right and the final `acc` is the return value of `foldlAttrs`.
 
-    Attention:
-
+    ::: {.note}
     There is a completely different function `lib.foldAttrs`
     which has nothing to do with this function, despite the similar name.
+    :::
 
     # Inputs
 

lib/generators.nix

@@ -756,9 +756,9 @@ rec {
     * `indent` - initial indent.
     * `asBindings` - by default generate single value, but with this use attrset to set global vars.
 
-    Attention:
-
+    ::: {.note}
     Regardless of multiline parameter there is no trailing newline.
+    :::
 
     # Inputs
 

lib/options.nix

@@ -444,14 +444,18 @@ rec {
   /**
     Require a single definition.
 
-    WARNING: Does not perform nested checks, as this does not run the merge function!
+    ::: {.warning}
+    Does not perform nested checks, as this does not run the merge function!
+    :::
   */
   mergeOneOption = mergeUniqueOption { message = ""; };
 
   /**
     Require a single definition.
 
-    NOTE: When the type is not checked completely by check, pass a merge function for further checking (of sub-attributes, etc).
+    ::: {.note}
+    When the type is not checked completely by check, pass a merge function for further checking (of sub-attributes, etc).
+    :::
 
     # Inputs