Rollup merge of #68096 - varkor:diagnostic-cleanup, r=Centril

Clean up some diagnostics by making them more consistent

In general:

- Diagnostic should start with a lowercase letter.
- Diagnostics should not end with a full stop.
- Ellipses contain three dots.
- Backticks should encode Rust code.

I also reworded a couple of messages to make them read more clearly.

It might be sensible to create a style guide for diagnostics, so these informal conventions are written down somewhere, after which we could audit the existing diagnostics.

r? @Centril

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index bfadeafb7c7..fee7ace92ea 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -208,7 +208,7 @@ fn default_hook(info: &PanicInfo<'_>) {
                     let _ = writeln!(
                         err,
                         "note: run with `RUST_BACKTRACE=1` \
-                                           environment variable to display a backtrace."
+                                           environment variable to display a backtrace"
                     );
                 }
             }