Improve tutorial for new users

* Mention support for tags, in particular stable releases.
* Mention that nightly --version might "lie" about their dates.
* Also fix some small typos in nearby paragraphs that I noticed.

Author: VorpalBlade

guide/src/tutorial.md

@@ -49,16 +49,20 @@ It will do a binary search between the start and end range to find exactly where
 
 [`--regress`]: usage.md#regression-check
 
-In our example, in just a few steps, we can we find that it stopped working on `nightly-2018-07-30`.
+> **Note**: You can also specify git tags as start and end points. This is particularly useful for stable releases e.g. `--start=1.88.0`, which will be automatically converted to the corresponding nightly date.
+
+In our example, in just a few steps, we can find that it stopped working on `nightly-2018-07-30`.
 
 If the regression is recent enough, then it will print out a list of PRs that were committed on that date.
-In this particular example, it is too old, so we'll need to manually inspect the git log to see which PR's were merged.
+In this particular example, it is too old, so we'll need to manually inspect the git log to see which PRs were merged.
 
 If the nightly was within the last 167 days, then `cargo-bisect-rustc` will then start bisecting those individual PRs.
 
 After finding potential candidates, you can go inspect those PRs to see which one is the likely cause.
 In this case, since the ICE was in MIR const propagation, and #51361 is the likely candidate since it modified const evaluation.
 
+> **Note**: A pitfall is that if you use something like `rustc +nightly --version` to figure out the version you are on it will often identify a date that is one day early from the nightly toolchain version. E.g. `nightly-2025-07-19` will say `2025-07-18`, since that is when the most recent commit was merged, even though the toolchain was built on the 19th.
+
 ## Testing interactively
 
 Pass/fail of `cargo build` may not be what you're after.