Upgrade mdbook-linkcheck

Link check at build

Install linkcheck with cargo

Optional linkcheck

Author: ehsanmok

.github/workflows/gh-pages.yml

@@ -14,15 +14,13 @@ jobs:
         uses: peaceiris/actions-mdbook@v1
         with:
           mdbook-version: 'latest'
-          
-      - name: Link check
-        run: |
-          curl -LSfs https://japaric.github.io/trust/install.sh | \
-          sh -s -- --git Michael-F-Bryan/mdbook-linkcheck
-      
+
+      # - name: Link check
+      #   run: cargo install mdbook-linkcheck
+
       - name: Build
         run: cd book && mdbook build
-      
+
       - name: Deploy
         uses: peaceiris/actions-gh-pages@v3
         with:

book/book.toml

@@ -15,6 +15,7 @@ preferred-dark-theme = "Rust"
 enable = true
 
 [output.linkcheck]
+optional = true
 follow-web-links = true
 exclude = ['blacklivesmatter\.com']
 warning-policy = "error"

book/src/01_calculator/grammar_lexer_parser.md

@@ -27,7 +27,7 @@ This grammar basically defines the syntax and semantics where
 * unary or binary expressions are made of `Term` and `Operator` (`"+"` and `"-"`)
 * the only *atom* is integer `Int`
 
-Given our grammar, we will use [pest](https://bitbegin.github.io/pest-rs/) which is a powerful *parser generator* of PEG grammars. (For more details on pest, checkout the [pest book](https://bitbegin.github.io/pest-rs/book/)
+Given our grammar, we will use [pest](https://pest.rs/) which is a powerful *parser generator* of PEG grammars. (For more details on pest, checkout the [pest book](https://pest.rs/book/)
 
 `pest` *derives* the parser `CalcParser::parse` from our grammar