feat(brightness): add brightness adjust filter (-B flag)

[saumya1317]

This pull request implements the Brightness Adjust filter (-B flag) for the image filtering application. It allows users to either increase or decrease the brightness of an image by providing an integer value with the flag. The filter and its usage are both implemented in code and described in the updated README.

Issues

Example:

Closes #17

[harshsankhla18]

Hey, Just do one thing Solve only brightness adjust filter in this issue. And For Threshold filter add the description later when i assign you that in other PR. And Also Re-Send the separated PRs with brightness and then if no one Sends the PR then I will accept the threshold PR as you have enough contriubtions on this project already.

[saumya1317]

okay i have removed threshold one addded brightness algo

[harshsankhla18]

@saumya1317 Correct your PR title to conventional commit title otherwise it will not pass the checks .

[harshsankhla18]

The brightness filter is not working for gcc, though i have merged PR , please correct it for gcc and its use case should be "filter -B 40 input.bmp output.bmp" , your code is not working properly . Correct it fast otherwise you points will be deducted again.