fix(doc): config file emplacements in README

[benoitlx]

Apologize if I'm not right, but it seems to me that some of the config file emplacements described in the README are not right (those beginning with "[[user config dir]]") or at least non consistent with what's being outputted by wishlist --help:

Flags:
  -c, --config string                    Path to the config file to use. Defaults to, in order of preference: .wishlist/config.yaml, .wishlist/config.yml, .wishlist/config, 
+ /var/home/bleroux/.config/wishlist.yaml, 
+ /var/home/bleroux/.config/wishlist.yml, 
+ /var/home/bleroux/.config/wishlist, 
/var/home/bleroux/.ssh/config, /etc/ssh/ssh_config

while in the README it says the following:

+ [[user config dir]]/wishlist/config.yaml
+ [[user config dir]]/wishlist/config.yml
+ [[user config dir]]/wishlist/config

Note: I added line breaks and markdown diff format for better clarity

Running wishlist v0.15.2

• I have read CONTRIBUTING.md.
• I have created a discussion that was approved by a maintainer (for new features).