docs: improve code formatting and readability in readme examples

[feO2x]

This pull request focuses on improving the readability and formatting of the example code in the readme.md file. The changes primarily involve restructuring method calls and constructor invocations to use multiline formatting for better clarity and consistency.

Code readability improvements:

• Reformatted the constructor of SomeService and the ProcessStreamAsync method to use multiline parameter formatting, enhancing readability.
• Updated the example demonstrating the use of HashingPlugin to format the call to CopyToTemporaryStreamAsync across multiple lines, improving clarity.
• Enhanced the section on CopyToHashCalculator by explicitly showing multiline instantiation of hash calculators and updating the associated example code for better control and readability.