docs(tutorials): fix typos in simple-date-clock-application

[iamludal]

Implemented solution

Some typo fixes in the simple-date-clock-application tutorial documentation.

How to test this PR

Read the updated version of the documentation.

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Documentation (select one):

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Nice to have (if relevant):

• Screenshots of the changes
• Explanatory video/animated gif

[filippomc]

Looks good, thanks @iamludal for your first PR!