Ignore missing_panics_doc pedantic clippy lint

    warning: docs for function which may panic missing `# Panics` section
       --> src/lib.rs:836:5
        |
    836 |     pub fn new(ch: char, spacing: Spacing) -> Self {
        |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
    note: first possible panic found here
       --> src/lib.rs:846:13
        |
    846 |             panic!("unsupported proc macro punctuation character {:?}", ch);
        |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#missing_panics_doc
        = note: `-W clippy::missing-panics-doc` implied by `-W clippy::pedantic`
        = help: to override `-W clippy::pedantic` add `#[allow(clippy::missing_panics_doc)]`

Author: dtolnay

src/lib.rs

@@ -102,6 +102,7 @@
     clippy::let_underscore_untyped,
     clippy::manual_assert,
     clippy::manual_range_contains,
+    clippy::missing_panics_doc,
     clippy::missing_safety_doc,
     clippy::must_use_candidate,
     clippy::needless_doctest_main,