Added my own bg music and tile music

[supunTE]

• Read and understood [see CONTRIBUTING.md]
• Included a preview link and screenshot showing after and before the changes.
• Included a description of change below.
• Tried to squash.

Changes done in this Pull Request

• I added my own bg music and tile music.
• https://stedirisuriya.github.io/labyrinth/

[abishekvashok]

Can you properly license these content as well?

[supunTE]

@abishekvashok I think licensing is not required.
As the task said,

we recommend choosing the license CC-BY or CC-BY-SA if you like others to remix or CC-BY-ND if you do not like people editing your song.

it's only needed if I don't like to change it by others. So I think it's not required.
@niccokunzmann What's your idea?

[abishekvashok]

Please choose one.

[supunTE]

@abishekvashok OK. I added one.

[niccokunzmann]

If you do not add a license, the song is GPL licensed.

[supunTE]

@niccokunzmann I added licenses. Please, could you merge this now?

[niccokunzmann]

I had a look at the files. You are proposing to use WAV which is uncompressed and huge. This makes cloning the repository slower. Would it be ok for you to add it in e.g. ogg format?

[supunTE]

@niccokunzmann I converted them to .ogg format thank you!

[niccokunzmann]

Thanks!

[abishekvashok]

Task link: https://codein.withgoogle.com/dashboard/task-instances/4871848987721728/

[supunTE]

Thank you!