Minor English-language improvements in installation.md

[saifkhichi96]

Motivation and context

There are some poorly written sentences in documentation pages. For example:

You can use a share storage for data uploading during you are creating a task. To do that you can mount it to CVAT docker container.

These make the documentation look a little informal, and since Installation Guide is probably the first page most new CVAT users visit, I updated some of the sentences on this page to have a better structure / sound more formal.

How has this been tested?

This change did not require any tests.

Checklist

• I submit my changes into the develop branch
• I have added a description of my changes into the CHANGELOG file
• I have updated the documentation accordingly
• I have added tests to cover my changes
• I have linked related issues (see GitHub docs)
• I have increased versions of npm packages if it is necessary
  (cvat-canvas,
  cvat-core,
  cvat-data and
  cvat-ui)

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.

[nmanovic]

@saifkhichi96 , thanks for the contribution!