Improve documentation contents

[fktn-k]

Description

(This is actually not a bug in the library sources.)

We have a number of documentations, e.g., comments in the library sources or documentation sources in docs/mkdocs/docs.
Since English is not my first language, however, the contents may be unclear, redundant or unnatural. They may also contain a number of typos.
Because documentation is a crucial factor (at least for me), I would like to ask for help so we can make them better.

Fixing just one typo is very welcome. Thanks in advance!

Reproduction steps

Just take a look at the documentation. You might find something that could be improved.

Expected vs. actual results

(Omitted since this issue doesn't report a bug in the library.)

Minimal code example

No response

Error messages

No response

Compiler and operating system

(Omitted since this issue doesn't report a bug in the library.)

Library version

develop HEAD

Validation

• [ ] The bug also occurs if the latest version from the develop branch is used.
• [ ] I can successfully compile and run the unit tests.

[sndth]

Hi! I've created a pull request where I will be adding documentation fixes (only in the source code, meaning in strings and comments).