ci(doc consistency): check that lib.rs and README.md are consistent

.github/workflows/ci.yml

@@ -16,6 +16,11 @@ jobs:
         with:
           toolchain: stable
           components: rustfmt
+      - name: Install cargo-readme
+        run: cargo install cargo-readme
+      - name: Check doc consistency
+        shell: bash
+        run: diff -q README.md <(cargo readme) || echo "::error title='Inconsistent README.md and lib.rs'::Update lib.rs then use cargo-readme to update README.md"
       - name: rustfmt
         run: cargo fmt --all -- --check
       - name: docs

README.md

@@ -34,26 +34,29 @@ libraries and such might not want.
 
 ### Table of Contents <!-- omit in toc -->
 
-- [About](#about)
-- [Features](#features)
-- [Installing](#installing)
-- [Example](#example)
-- [Using](#using)
-  - [... in libraries](#-in-libraries)
-  - [... in application code](#-in-application-code)
-  - [... in `main()`](#-in-main)
-  - [... diagnostic code URLs](#-diagnostic-code-urls)
-  - [... snippets](#-snippets)
-  - [... help text](#-help-text)
-  - [... severity level](#-severity-level)
-  - [... multiple related errors](#-multiple-related-errors)
-  - [... delayed source code](#-delayed-source-code)
-  - [... handler options](#-handler-options)
-  - [... dynamic diagnostics](#-dynamic-diagnostics)
-  - [... syntax highlighting](#-syntax-highlighting)
-  - [... collection of labels](#-collection-of-labels)
-- [Acknowledgements](#acknowledgements)
-- [License](#license)
+- [`miette`](#miette)
+    - [About](#about)
+    - [Features](#features)
+    - [Installing](#installing)
+    - [Example](#example)
+    - [Using](#using)
+      - [... in libraries](#-in-libraries)
+      - [... in application code](#-in-application-code)
+      - [... in `main()`](#-in-main)
+      - [... diagnostic code URLs](#-diagnostic-code-urls)
+      - [... snippets](#-snippets)
+      - [... help text](#-help-text)
+      - [... severity level](#-severity-level)
+      - [... multiple related errors](#-multiple-related-errors)
+      - [... delayed source code](#-delayed-source-code)
+      - [... Diagnostic-based error sources.](#-diagnostic-based-error-sources)
+      - [... handler options](#-handler-options)
+      - [... dynamic diagnostics](#-dynamic-diagnostics)
+      - [... syntax highlighting](#-syntax-highlighting)
+      - [... collection of labels](#-collection-of-labels)
+    - [MSRV](#msrv)
+    - [Acknowledgements](#acknowledgements)
+    - [License](#license)
 
 ### Features
 
@@ -665,7 +668,7 @@ println!("{:?}", report)
 
 <!-- TODO: screenshot goes here once default Theme is decided -->
 
-To use the built-in highlighting functionality, you must enable the
+To use the bublablablailt-in highlighting functionality, you must enable the
 `syntect-highlighter` crate feature. When this feature is enabled, `miette` will
 automatically use the [`syntect`] crate to highlight the `#[source_code]`
 field of your [`Diagnostic`].