cli: make -d a short flag for --max-depth

Interestingly, ripgrep now only has two available ASCII letter short
flags remaining: -k and -y.

Closes #2643, Closes #2644

CHANGELOG.md

@@ -36,6 +36,8 @@ Feature enhancements:
   When `extra-verbose` mode is enabled in zsh, show extra file type info.
 * [FEATURE #2409](https://github.com/BurntSushi/ripgrep/pull/2409):
   Added installation instructions for `winget`.
+* [FEATURE #2643](https://github.com/BurntSushi/ripgrep/issues/2643):
+  Make `-d` a short flag for `--max-depth`.
 
 Bug fixes:
 

crates/core/flags/complete/rg.zsh

@@ -192,7 +192,7 @@ _rg() {
     $no"--no-max-columns-preview[don't show preview for long lines (with -M)]"
 
     + '(max-depth)' # Directory-depth options
-    '--max-depth=[specify max number of directories to descend]:number of directories'
+    {-d,--max-depth}'[specify max number of directories to descend]:number of directories'
     '--maxdepth=[alias for --max-depth]:number of directories'
     '!--maxdepth=:number of directories'
 

crates/core/flags/defs.rs

@@ -3829,6 +3829,9 @@ impl Flag for MaxDepth {
     fn is_switch(&self) -> bool {
         false
     }
+    fn name_short(&self) -> Option<u8> {
+        Some(b'd')
+    }
     fn name_long(&self) -> &'static str {
         "max-depth"
     }
@@ -3873,6 +3876,9 @@ fn test_max_depth() {
     let args = parse_low_raw(["--max-depth", "5"]).unwrap();
     assert_eq!(Some(5), args.max_depth);
 
+    let args = parse_low_raw(["-d", "5"]).unwrap();
+    assert_eq!(Some(5), args.max_depth);
+
     let args = parse_low_raw(["--max-depth", "5", "--max-depth=10"]).unwrap();
     assert_eq!(Some(10), args.max_depth);