fix(wget): add flag to wget subject

subjects/wget/README.md

@@ -169,6 +169,16 @@ example:
 $ go run . --mirror -X=/assets,/css https://example.com
 ```
 
+- [Convert Links for Offline Viewing](https://www.gnu.org/software/wget/manual/wget.html#The-%60--convert_002dlinks%60-Option) (`--convert-links`)
+
+> this flag will convert the links in the downloaded files so that they can be viewed offline, changing them to point to the locally downloaded resources instead of the original URLs.
+
+example:
+
+```console
+$ go run . --mirror --convert-links https://example.com
+```
+
 ### Hint
 
 You can take a look into the [html package](https://godoc.org/golang.org/x/net/html) for some help.\