Documentation in example config file values

[0xB10C]

specifically min_fork_height and max_interesting_heights should be documented.

fork-observer/config.toml.example

Lines 38 to 39 in 104f51f

	min_fork_height = 0
	max_interesting_heights = 100

see bitcoin-dev-project/warnet#507 (comment)

also, bitcoin-dev-project/warnet#507 (comment) might be worth to document