docs: add the zig linker to reference tables

docs/markdown/Reference-tables.md

@@ -76,6 +76,7 @@ These are return values of the `get_linker_id` method in a compiler object.
 | ccomp      | CompCert used as the linker driver          |
 | mwldarm    | The Metrowerks Linker with the ARM interface, used with mwccarm only |
 | mwldeppc   | The Metrowerks Linker with the PowerPC interface, used with mwcceppc only |
+| zig        | The Zig linker                              |
 
 For languages that don't have separate dynamic linkers such as C# and Java, the
 `get_linker_id` will return the compiler name.