Delete length check (#1952)

It's super annoying to be forced to use this bad convention, and
apparently everyone agrees. The only reason no improvements have been
done is because those were blocked on writing a better checker.

I strongly believe that no checker is better than a bad checker, so
let's just delete it in the meantime. I kindly asked anyone who sees
this to complain about overly long sentences in review in the future, I
think we can make this turn out fine.

.github/workflows/ci.yml

@@ -42,12 +42,6 @@ jobs:
             ~/book/linkcheck
           key: ${{ runner.os }}-${{ hashFiles('./book/linkcheck') }}
 
-      - name: Check line lengths
-        if: github.event_name != 'push'
-        run: |
-          shopt -s globstar
-          MAX_LINE_LENGTH=100 bash ci/lengthcheck.sh src/**/*.md
-
       - name: Install latest nightly Rust toolchain
         if: steps.mdbook-cache.outputs.cache-hit != 'true'
         run: |

README.md

@@ -64,25 +64,6 @@ We use `mdbook-linkcheck` to validate URLs included in our documentation.
 We use `mdbook-toc` to auto-generate TOCs for long sections. You can invoke the preprocessor by
 including the `<!-- toc -->` marker at the place where you want the TOC.
 
-### Pre-commit script
-
-We also test that line lengths are less than 100 columns. To test this locally,
-you can run `ci/lengthcheck.sh`.
-
-You can also set this to run automatically.
-
-On Linux:
-
-```bash
-ln -s ../../ci/lengthcheck.sh .git/hooks/pre-commit
-```
-
-On Windows:
-
-```powershell
-New-Item -Path .git/hooks/pre-commit -ItemType HardLink -Value $(Resolve-Path ci/lengthcheck.sh)
-```
-
 ## How to fix toolstate failures
 
 > **NOTE**: Currently, we do not track the rustc-dev-guide toolstate due to

src/contributing.md

@@ -316,9 +316,9 @@ There are issues for beginners and advanced compiler devs alike!
 
 Just a few things to keep in mind:
 
-- Please limit line length to 100 characters.
-  This is enforced by CI,
-  and you can run the checks locally with `ci/lengthcheck.sh`.
+- Please try to avoid overly long lines and use semantic line breaks (so break the line after a sentence).
+  There is no strict limit on line lengths, let the sentence or part of the sentence flow to its proper end on the same line.
+  There is currently nothing stopping anyone from creating overly long lines, just do your best to avoid them.
 
 - When contributing text to the guide, please contextualize the information with some time period
   and/or a reason so that the reader knows how much to trust or mistrust the information.