Consolidating the existing RingBuffer Implementation.

[professorabhay]

• Created a new lib/free-queue/ directory under src/
• Added free-queue.js and free-queue-sab.js files
• Added the code
• updated the imports/usage with new classes

[mjwilson-google]

Thanks for the change!

When I tested this, I needed to add the following to the "// Passthrough files via these glob patterns." list in .eleventy.js:
'src/lib/**/*.js',

Once I did that, the four examples worked as expected. Please include this change and I will approve the PR.