Fix TOC docs

docs/extensions/toc.md

@@ -198,14 +198,14 @@ The following options are provided to configure the output:
 
 * **`toc_depth`**
     Define the range of section levels to include in the Table of Contents.
-    A single integer (b) defines the bottom section level (<h1>..<hb>) only.
-    A string consisting of two digits separated by a hyphen in between ("2-5"),
-    define the top (t) and the bottom (b) (<ht>..<hb>). Defaults to `6` (bottom).
+    A single integer (`b`) defines the bottom section level (`<h1>..<hb>`) only.
+    A string consisting of two digits separated by a hyphen in between (`"2-5"`),
+    define the top (`t`) and the bottom (`b`) (`<ht>..<hb>`). Defaults to `6` (bottom).
 
     When used with conjunction with `baselevel`, this parameter will not
     take the fitted hierarchy from `baselevel` into account. That is, if
-    both `toc_depth` and `baselevel` are 3, then only the highest level
-    will be present in the table. If you set `baselevel` to 3 and
-    `toc_depth` to '2-6', the *first* headline will be `<h3>` and so still
+    both `toc_depth` and `baselevel` are `3`, then only the highest level
+    will be present in the table. If you set `baselevel` to `3` and
+    `toc_depth` to `"2-6"`, the *first* headline will be `<h3>` and so still
     included in the Table of Contents. To exclude this first level, you
-    have to set `toc_depth` to '4-6'.
+    have to set `toc_depth` to `"4-6"`.