Updated manual.tex

- fixed two tiny typos
- fixed example code
- example code: replaced the f string interpolator with the s string interpolator (features of f srting interpolator are not used here)
Updated manual.tex

- fixed "Map Events" example (added string interpolator `s`)
Updated manual.tex

- fixed typos
- fixed code examples
Merge pull request #5 from sprankhub/patch-3

Updated manual.tex
Merge pull request #4 from sprankhub/patch-2

Updated manual.tex
Merge branch 'master' of https://github.com/guidosalva/REScala
Merge pull request #3 from sprankhub/patch-1

Updated manual.tex
rewrite of the signal macro to get rid of the type checker workaround, hopefully this will solve some problems with using the macro like this one: https://github.com/guidosalva/examples/pull/4/files#r11724000