Translated and modularized the extensions into TypeScript *.ts
files, in the extensionsTS directory. The compiled files are present in
that directory as *.js files, which can be required or imported even if
you are not using TypeScript. (Caution: all of the script in the HTML
samples in the extensions directory have been split out into ...Script.ts files, so try not to be confused by the corresponding *.js
files, which will have Script in their names.)