Minecraft to minetest texture pack converter

Minetest is a free Minecraft-like infinite-world block sandbox game. It's full of fun. It can be installed on Linux operating system, like Ubuntu. The installation is easy, just following the instructions on Minetest official website. The only problem is that the texture of the official release is ugly. One can download the third party texture files from internet. One can also convert the texture files from Minecraft using the converter here (https://github.com/minermoder27/minecraft-to-minetest-tp-conv). People may meet problems with this converter. There are two ways to make it run correctly.
The first one is  moving "mc-to-mt-tp-conv" folder to inside of the assets folder. Then run the script conv.sh.
If one put "mc-to-mt-tp-conv" folder and assets folder in the same folder, one has to change two lines of the script file conv.sh as the following.
FILES=$(dirname "$0")/assets/minecraft/textures/blocks/*.png
FILES=$(dirname "$0")/assets/minecraft/textures/items/*.png

If one doesn't follow this instruction, the script wouldn't work.