Yes, you can make your own texture packs! It can be a little complicated though. π
First, you need to download a sample texture pack, for example our Lucky Blocks texture - https://s3-eu-west-1.amazonaws.com/modding.codekingdoms.com/resourcePacks/luckyBlocks.zip
Next, you need to unzip it and modify it to include whichever textures you want to add yourself.
Finally, compress it again and upload it to a free cloud service like Google Drive or Dropbox, where you can get a direct link to the file and add that into your code using the setResourcePackUrl method (like the code in Lucky Blocks)!