Replace 'argument' by 'parameter' in 'contour_map.py' and 'lines.py'

[yvonnefroehlich]

Description of proposed changes

Related to the decision in issue #886 this PR aims to update the tutorial Creating a map with contour lines to use 'parameter' instead of 'argument'.

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If wrapping a new module, open a 'Wrap new GMT module' issue and submit reasonably-sized PRs.
• If adding new functionality, add an example to docstrings or tutorials.

Slash Commands

You can write slash commands (/command) in the first line of a comment to perform
specific operations. Supported slash commands are:

• /format: automatically format and lint the code
• /test-gmt-dev: run full tests on the latest GMT development version

[weiji14]

Thanks @yvonnefroehlich, could you please also change 'argument' -> 'parameter' in:

pygmt/examples/tutorials/basics/lines.py

Line 47 in d80b986

# additional line. Arguments such as ``region``, ``projection``, and ``frame``

[yvonnefroehlich]

Thanks @yvonnefroehlich, could you please also change 'argument' -> 'parameter' in:

pygmt/examples/tutorials/basics/lines.py

Line 47 in d80b986

# additional line. Arguments such as ``region``, ``projection``, and ``frame``

Thanks @weiji14! Done in a7b8e89.

[weiji14]

Thanks!