Docs bug: fish shell interactive instructions not accurate

[pikeas]

https://mise.jdx.dev/dev-tools/shims.html#how-to-add-mise-shims-to-path

echo 'mise activate fish --shims | source' >> ~/.config/fish/config.fish
echo 'mise activate fish | source' >> ~/.config/fish/fish.config

fish.config is not a file sourced by fish shell, only config.fish is. Enabling non-shim activation should be done in an if status is-interactive block in the main config.fish file

[roele]

PR #8798