I found the following two tool useful in creating templates:
1. To escape the characters that need escaping:
(the instructions in https://github.com/blach/Textastic-Customization, do not mention escaping characters beyond tabs and newlines, but one has to also).
2. To check the syntax of the json file (otherwise Textastic will not load it):
I don't do java, so these two tool were very useful.
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