Bad example in Crate docs, from_file not implemented in ManifestStore

[ronald-das]

Hi, while going through the example in https://docs.rs/c2pa/latest/c2pa/#example-reading-a-manifeststore
Am getting not implemented error (E0599)

error[E0599]: no function or associated item named `from_file` found for struct `ManifestStore` in the current scope
 --> src/main.rs:4:41
  |
4 |     let manifest_store = ManifestStore::from_file("tests/fixtures/C.jpg")?;
  |                                         ^^^^^^^^^ function or associated item not found in `ManifestStore`

My cargo.toml file

[dependencies]
c2pa = "0.11.0"

[ronald-das]

After going through the struct documentation https://docs.rs/c2pa/latest/c2pa/struct.ManifestStore.html#method.from_file , file_io feature needs to enabled for it to work.

New Cargo.toml file

[dependencies]
c2pa = {version="0.11.0", features=["file_io"]}

[scouten-adobe]

@ronald-das thanks for bringing this to our attention. I'm reopening the ticket. I think we should add a note in the README to mention that file_io feature is needed. @crandmck or @gpeacock, would one of you please add this?

[crandmck]

Should we just change the Cargo.toml file in "Usage" section to be

c2pa = {version="0.11.0", features=["file_io"]}

or should we qualify it by just adding something like "If you want to read or write a manifest file, add this to your Cargo.toml..." ?

[gpeacock]

We should describe the features somewhere and how and when to use them. Since the file_io feature enables a lot of the sdk, we should make special mention of it with something like the above. I'd be in favor of having the example include it with a note that if building for WASM you should leave it out.

[crandmck]

Addressed (partially, at least) by #93.