Describe the bug
The impl DiscordHandler trait object stored by Discord and its internal handler task is boxed in its current form. As far as I can tell, this is just an unnecessary(albeit minor) performance hit(introduces an unnecessary runtime vtable lookup), and converting it to impl DiscordHandler would only serve to improve performance. That being said, if there are legitimate reasons, please let me know!

Additional context
Relevant Discord ctor code
Relevant handler_task code

Describe the bug
Alright, I've figured it out! This bug specifically occurs when anything .awaits a Discord request, and the IO handler restarts for whatever reason. The awaits hang perpetually.

To Reproduce
Steps to reproduce the behavior:

1. Write some code which does the following:
   1. Connects to discord
   2. Sends a periodical request of some kind, I've been using activity updates.
   3. Make sure it logs when it does, or in some way shows that it's running
2. Run it with Discord open
3. Kill discord and reopen it
4. Note how the logging suddenly pauses

Expected behavior
For an error to be returned, or, ideally, the request to be transparently resent in some way.

Device:
ArchLinux, kernel 6.1.19, rustc 1.66.0-nightly

Describe the bug
discord_sdk::activity::Assets::{large_image, small_image} don't properly validate what is passed in to them. The 32-char limit applies to keys, but not to proxied URLs, which have no such length limit.

Expected behavior
For it to not incorrectly discard data.

Since Discord themselves don't provide any kind of headless test server for RPCs, there's no good way to do automated testing in a normal headless environment since it requires installing the full Discord app, and logging into it, which, AFAICT, is impossible in a headless environment as Discord doesn't support command line arguments.

While testing locally in a regular desktop environment works, this is tedious and easy to miss stuff, especially from outside contributors, so I think it makes sense to make a unix domain socket/named pipe server that tests can fill out with preplanned responses/events to add a bit more sanity checking to CI.

We're currently using a fork of tokio 1.7 to add some needed methods to NamedPipeClient as it is brand new in 1.7, this is necessary for us to be able to publish new releases.

thread 'main' panicked at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/alloc/src/string.rs:1396:13:
assertion failed: self.is_char_boundary(new_len)
stack backtrace:
   0: rust_begin_unwind
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:645:5
   1: core::panicking::panic_fmt
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:72:14
   2: core::panicking::panic
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:144:5
   3: discord_sdk::activity::truncate::{{closure}}
   4: discord_sdk::activity::ActivityBuilder::details

To Reproduce
Steps to reproduce the behavior:

1. Call discord_sdk::activity::ActivityBuilder::default().details("xäääääääääääääääääääääääääääääääääääääääääääääääääääääääääääääääää")

Is your feature request related to a problem? Please describe.
Not really

Describe the solution you'd like
Although the features aren't really new anymore, it would be great to still have the functionality within this library. The two features which i primarily have in mind are the following:

• Asset keys being urls
• Buttons

Describe alternatives you've considered
For url asset keys i can bypass the check by setting it not using the method eg:

let mut assets = Assets::default();
assets.large_image = Some(game_thumbnail.clone());
assets.large_text = Some(game_name.clone());

But to get buttons to work i would figure i need to do much more and alter the current source code.

Additional context
n/a

Even though Voice is being deprecated, we're hoping to use Lobbies in the short term to get voice chat support. This works well, but one missing piece is that when joined to a lobby voice channel, you hear everyone, and everyone can hear you, which is fine for internal playtests, but might be a bit tedious with real users. Adding support for the Voice API in the SDK would allow us to add support for self muting and un/muting of other players in the lobby.

Describe the bug
The README does not correctly link back to multiple other markdown files. This leads to dead links on the docs.rs page.

To Reproduce
Steps to reproduce the behavior:

1. Go to the docs.
2. Click on 'Contributor Guide'
3. See error

Expected behavior
I expect the links to work.