Typo fixes in about.pod6 and predef search items

Author: sjn

doc/Language/about.pod6

@@ -112,7 +112,7 @@ is always considered a definition)
 
 Then the results on the rendered page:
 
-=item X<C<How to use the Z infix> | infix,Z> (This a special case, which
+=item X<C<How to use the Z infix> | infix,Z> (This is a special case, which
 is always considered a definition)
 
 =item C<The Z Infix>

predefined-search-items

@@ -1,3 +1,3 @@
-{ category: "Syntax", value: "# sinle-line comment", url: "/language/syntax#Single-line_comments" },
+{ category: "Syntax", value: "# single-line comment", url: "/language/syntax#Single-line_comments" },
 { category: "Syntax", value: "#` multi-line comment", url: "/language/syntax#Multi-line_/_embedded_comments" },
 { category: "Signature", value: ";; (long name)", url: "/type/Signature#index-entry-Long_Names" },