Fixing simple typos

[kinow]

Hi!

Had some spare time in-between Java deployments, and decided to quickly try to read and follow parts of the workshop :)

Here's some simple typos found in the project README.md.

• s/a//
• s/mentionned/mentioned/
• s/mathematic/mathematical/
• s/dictionnaries/dictionaries/
• s/pilar/pillar/
• s/assignements/assignments/
• s/strenths/strengths/
• s/wich/which/

[kinow]

ps: successfully ran both notebooks. Will revisit notebook 02 to look at all those great links. Thanks Nico!!!