Improve the "meaning" command to handle missing words, modify the color of the output


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**Present behaviour** :
`jarvis meaning ` where unknown-word represents word not in the dictionary results in undefined output in the terminal.

**Expected behaivour** :
Display a sensible output (like 'sorry, couldn't find the word you are looking for') for the same, in addition, a bright yellow/cyan color on the meaning text would look good when output is available.

Start by locating the `meaning` command entry point and reproduce the undefined output with an unknown word. Trace the available-word output path as well; done means unknown words receive a sensible message and available meanings use a bright yellow or cyan color.

Written by the indexing model from the issue text.