Disable links to empty chapters in book (#2589)

README.md

@@ -583,9 +583,8 @@ in your editor of choice so that I may include them here.
 Quick Start
 -----------
 
-See [the installation section](#installation) for how to install `just` on your
-computer. Try running `just --version` to make sure that it's installed
-correctly.
+See the installation section for how to install `just` on your computer. Try
+running `just --version` to make sure that it's installed correctly.
 
 For an overview of the syntax, check out
 [this cheatsheet](https://cheatography.com/linux-china/cheat-sheets/justfile/).

crates/generate-book/src/main.rs

@@ -185,13 +185,20 @@ fn main() -> Result {
         HeadingLevel::H5 => 4,
         HeadingLevel::H6 => 5,
       };
-      writeln!(
+
+      write!(
         summary,
-        "{}- [{}]({filename}.md)",
+        "{}- [{}](",
         " ".repeat(indent * 4),
         chapter.title(),
       )?;
 
+      if chapter.events.len() > 3 {
+        write!(summary, "{filename}.md")?;
+      }
+
+      writeln!(summary, ")")?;
+
       filenames.insert(filename);
     }