fix for invalid brace sequence expressions; cosmetic fix to help builtin; documentation and copyright updates; bump version to bash-5.3-rc1; cosmetic locale fixes

NEWS

@@ -143,6 +143,9 @@ uu. If `exit' is run in a trap and not supplied an exit status argument, it
     `top level' and would cause the trap to end (that is, not in a subshell).
     This is from Posix interp 1602.
 
+vv. There is a new `fltexpr' builtin to perform floating-point arithmetic
+    similarly to `let'.
+
 2. New Features in Readline
 
 a. Output a newline if there is no prompt and readline reads an empty line.
@@ -190,6 +193,9 @@ m. The default value for `readline-colored-completion-prefix' no longer has a
 n. There is a new bindable command, `export-completions', which writes the
    possible completions for a word to the standard output in a defined format.
 
+o. Readline can reset its idea of the screen dimensions when executing after
+   a SIGCONT.
+
 -------------------------------------------------------------------------------
 This is a terse description of the new features added to bash-5.2 since
 the release of bash-5.1.  As always, the manual page (doc/bash.1) is