enable docs lints, add to CI; add cargo doc task

.github/workflows/ci.yml

@@ -52,3 +52,4 @@ jobs:
       # We care that the benchmarks build and run, not about their numeric output.
       # To keep the CI a bit leaner, do this in the dev profile.
       - run: cargo build --locked --all-targets
+      - run: cargo doc --document-private-items

.vscode/tasks.json

@@ -0,0 +1,17 @@
+{
+	"version": "2.0.0",
+	"tasks": [
+		{
+			"type": "cargo",
+			"command": "doc",
+			"problemMatcher": [
+				"$rustc"
+			],
+			"group": {
+				"kind": "build",
+				"isDefault": false
+			},
+			"label": "rust: cargo doc"
+		}
+	]
+}

Cargo.toml

@@ -67,3 +67,13 @@ variant_size_differences = "deny"
 [lints.clippy]
 pedantic = { level = "deny", priority = -1 }
 missing_errors_doc = "allow"
+
+[lints.rustdoc]
+bare_urls = "deny"
+broken_intra_doc_links = "deny"
+invalid_codeblock_attributes = "deny"
+invalid_html_tags = "deny"
+invalid_rust_codeblocks = "deny"
+missing_crate_level_docs = "deny"
+private_intra_doc_links = "deny"
+unescaped_backticks = "deny"