Update default config file, add comment about tmux mouse scrolling support

src/bin/bat/config.rs

@@ -43,21 +43,30 @@ pub fn generate_config_file() -> bat::errors::Result<()> {
         }
     }
 
-    let default_config = r#"# bat config
+    let default_config = r#"# This is `bat`s configuration file. Each line either contains a comment or
+# a command-line option that you want to pass to `bat` by default. You can
+# run `bat --help` to get a list of all possible configuration options.
 
-# Specify desired theme (e.g. "TwoDark").  Issue `bat --list-themes` for a list of all available themes
+# Specify desired highlighting theme (e.g. "TwoDark"). Run `bat --list-themes`
+# for a list of all available themes
 #--theme="TwoDark"
 
-# Enable this to use italic text on the terminal (not supported on all terminals):
+# Enable this to use italic text on the terminal. This is not supported on all
+# terminal emulators (like tmux, by default):
 #--italic-text=always
 
 # Uncomment the following line to disable automatic paging:
 #--paging=never
 
-# Use C++ syntax for .ino files
-#--map-syntax "*.ino:C++"
+# Uncomment the following line if you are using less version >= 551 and want to
+# enable mouse scrolling support in `bat` when running inside tmux. This might
+# disable text selection, unless you press shift.
+#--pager="--RAW-CONTROL-CHARS --quit-if-one-screen --mouse"
 
-# Use ".gitignore"-style highlighting for ".ignore" files
+# Syntax mappings: map a certain filename pattern to a language.
+#   Example 1: use the C++ syntax for .ino files
+#   Example 2: Use ".gitignore"-style highlighting for ".ignore" files
+#--map-syntax "*.ino:C++"
 #--map-syntax ".ignore:Git Ignore"
 "#;