No way to enable the `url-encoding` feature for manganis

[rambip]

Problem

manganis-macro has the feature url-encoded, but not manganis.

When I use mg!(image("").url_encoded()), it says that I must enable the url-encoded feature, but I cannot do it directly.

In addition, I cannot run my tests with cargo test --all-features

manganis should export a url-encoded feature which would enable the corresponding one in manganis-macro