Prevent clap from switching to multiline format for short help

Ref clap-rs/clap#3300
Fixes #377

src/cli.rs

@@ -20,6 +20,7 @@ use crate::utils::bat::output::PagingMode;
  version,
  color = ColorChoice::Always,
  setting(AppSettings::DeriveDisplayOrder),
+ term_width(usize::MAX),
  after_long_help = "\
 GIT CONFIG
 ----------
@@ -729,8 +730,7 @@ pub struct Opt {
  #[clap(
  long = "merge-conflict-theirs-diff-header-decoration-style",
  default_value = "box",
- // See https://github.com/clap-rs/clap/issues/3300
- value_name = "STYLE> "
+ value_name = "STYLE"
  )]
  /// Style string for the decoration of the header above the 'theirs' merge conflict diff.
  ///