fix: corrected parameters and enhanced the description of interpolate…

[OwenSamuel]

…_color within image_mobject

Overview: What does this pull request change?

Corrected the code comment parameters for image_mobject/interpolate_color as mobject1 was duplicated. Updated the description to refer to the ImageMobject not just to the array of pixel color values.

Motivation and Explanation: Why and how do your changes improve the library?

To make the description more understandable and to correct the mistake.

Further Information and Comments

I have updated the description to my understanding but I am new to manim so please double check.

Attempts to fix issue #2918

Reviewer Checklist

• [ ] The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• [ ] If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• [ ] If applicable: newly added functions and classes are tested