Help links to TortoiseGit site don't open in a sensible browser

What steps will reproduce the problem?

1. Open TortoiseGitMerge
2. Open Help, e.g. with button in top right corner of menu bar
3. Click "TortoiseGitMerge is free!" link in table of contents
4. Click the link for https://tortoisegit.org/sourcecode

What is the expected output? What do you see instead?

I expected my system default browser to open the site. Instead, the integrated CHM browser tried to open it, and returned dozens of modal script error messages.

What version of TortoiseGit and Git are you using? On what operating system?

TortoiseGit 2.12.0.0 (C:\Program Files\TortoiseGit\bin)
git version 2.33.0.windows.1 (C:\Program Files\Git\bin; C:\Program Files\Git\mingw64; C:\Program Files\Git\etc\gitconfig) Windows 8.1

Please provide any additional information below.

The context menu for the problematic link is unhelpful, offering no way to open in an external browser or easily copy the link.

Help opened from TortoiseGit dialog boxes (e.g. commit) has the same basic problem of opening only in the integrated browser, but several of those links are less troublesome as they don't spam errors.