0.12.0 - TVM improvements

• 0.12.0 (2024-06-24)
  • Bug Fix: update logic that determines when the comma , character can
    be inserted into the input buffer
    • some internal routines were still looking at the last character in the
      input buffer, instead of the character to the left of the current
      cursor
      • prevented comma insertion when the cursor was scrolled into the
        middle of the input buffer
      • updated to look at the char to the left of cursor
    • update logic that handles left and right braces { }
      • comma now allowed only inside an open left-brace {
      • comma no longer allowed after the last closing right-brace }
  • TVM
    • reduce rounding errors when PYR==CYR, the most common case in the US
      at least
    • improve logic for appending the "overridden" dot after the IYR1,
      IYR2, and TMAX menu items
    • add C/YR menu (number of compoundings per year)
      • uses the same variable as the C/Y variable of the "Finance" app
        in TI-OS
      • supports 2ND C/YR to retrieve its value, just like 2ND P/YR
      • setting P/YR also sets C/YR (consistent with the behavior of
        the "Finance" app in TI-OS
      • setting C/YR does not change P/YR (same as "Finance" app)
    • add a dot to P/YR and C/YR if they differ from their default value
      of 12, allows users to quickly see if those values are different from
      the default
    • make TVM Solver more robust under certain edge cases, especially near
      I%YR ~ 0%
    • change initial guess of IYR1 to -50% to support negative interest
      rates by default
      • keep default value of IYR2 at 100%
    • synchronize the BEG/END flag of RPN83P with the BEGIN/END
      flag of the "Finance" app provided by TI-OS
    • display status message 'TVM Calculated (Multiple)' if the TVM equation
      has 2 solutions, but only one of them was found
  • docs
    • simplify pandoc processing pipeline
    • change PDF font to FreeSerif and FreeMono to render the U+2220 (angle)
      symbol properly