Let me know if you found a grammar/spelling mistake or find a section hard to understand.
Write me a mail to dittrich.c.jan AT gmail.com
Alternatively, use the problem report google form
Please copy-paste the concerning text, so I can be sure what part to correct. If you find a grammar/spelling mistake, please tell what the problem is. If you let me know about a section that is hard to understand, please describe briefly, what you found confusing or complicated.
I’d be also glad to hear suggestions for additional or changed content. However, it should match the concept.