Update docs for base64 filters

Author: ashishajr

docs/filters.md

@@ -61,24 +61,46 @@ jsonpath "$.books" count == 12
 
 ### base64Decode
 
-Decode a base 64 encoded string into bytes.
+Decode a [Base64 encoded string] into bytes.
 
 ```hurl
 GET https://example.org/api
 HTTP 200
 [Asserts]
-jsonpath "$.token" base64Decode == hex,e4bda0e5a5bde4b896e7958c;
+jsonpath "$.token" base64Decode == hex,3c3c3f3f3f3e3e;
 ```
 
 ### base64Encode
 
-Encode bytes into base 64 encoded string.
+Encode bytes into [Base64 encoded string].
 
 ```hurl
 GET https://example.org/api
 HTTP 200
 [Asserts]
-bytes base64Encode == "5L2g5aW95LiW55WM"
+bytes base64Encode == "PDw/Pz8+Pg=="
+```
+
+### base64UrlSafeDecode
+
+Decode a Base64 encoded string into bytes (using [Base64 URL safe encoding]).
+
+```hurl
+GET https://example.org/api
+HTTP 200
+[Asserts]
+jsonpath "$.token" base64UrlSafeDecode == hex,3c3c3f3f3f3e3e;
+```
+
+### base64UrlSafeEncode
+
+Encode bytes into Base64 encoded string (using [Base64 URL safe encoding]).
+
+```hurl
+GET https://example.org/api
+HTTP 200
+[Asserts]
+bytes base64UrlSafeEncode == "PDw_Pz8-Pg"
 ```
 
 ### count
@@ -331,3 +353,5 @@ bytes decode "gb2312" xpath "string(//body)" == "你好世界"
 [a specification format]: https://docs.rs/chrono/latest/chrono/format/strftime/index.html
 [XPath]: https://en.wikipedia.org/wiki/XPath
 [JSONPath]: https://goessner.net/articles/JsonPath/
+[Base64 encoded string]: https://datatracker.ietf.org/doc/html/rfc4648#section-4
+[Base64 URL safe encoding]: https://datatracker.ietf.org/doc/html/rfc4648#section-5