Docs: replace AMQP 0-9-1 reference links

[michaelklishin]

They have been moved to a GitHub repository [1].

Closes #153.

1. https://www.rabbitmq.com/amqp-0-9-1-reference.html

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.89%. Comparing base (d350041) to head (6df0390).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #159      +/-   ##
==========================================
+ Coverage   85.86%   85.89%   +0.02%     
==========================================
  Files          40       40              
  Lines        6658     6657       -1     
==========================================
+ Hits         5717     5718       +1     
+ Misses        941      939       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[michaelklishin]

The lint failure seemingly has nothing to do with this change but rather a change in the clippy version used? or the module was previously cached and re-compiled:

error: operator precedence can trip the unwary
   --> amqprs/src/frame/content_header.rs:545:21
    |
    |                 if (flags[0] & 1 << 7) != 0 {
    |                     ^^^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `flags[0] & (1 << 7)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence
    = note: `-D clippy::precedence` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::precedence)]`

I'd be happy to address the warning if @gftea wants me to.

[gftea]

@michaelklishin thanks! Yes, must due to new clippy version, much appreciate if you could help fixing them

[michaelklishin]

@gftea done!

[gftea]

Thanks! @michaelklishin