I have a structure similar to the following:
/root/ /root/data/ /root/data/script.php /root/data/some.json /root/data/feature/one.json /root/data/feature/tw
you can place data/**/*.json in your .gitignore in /root directory to prevent multiple .gitignore files in different directories
data/**/*.json
.gitignore
/root
**/ - matches any count of subdirectories (including current)
**/
example: data/**/*.json record will ignore data/1.json, data/subfolder/2.json, data/../../3.json
data/1.json
data/subfolder/2.json
data/../../3.json