Removed the note about using forgit as a git subcommand from the 'tips' section (#321)

The note was redundant because it is explained in more detail in the 'git integration' section.

Author: sandr01d

README.md

@@ -344,7 +344,6 @@ export FORGIT_LOG_FZF_OPTS='
 - Most of the commands accept optional arguments (eg, `glo develop`, `glo f738479..188a849b -- main.go`, `gco master`).
 - `gd` supports specifying revision(eg, `gd HEAD~`, `gd v1.0 README.md`).
 - Call `gi` with arguments to get the wanted `.gitignore` contents directly(eg, `gi cmake c++`).
-- You can use the commands as sub-commands of `git`, see [#147](https://github.com/wfxr/forgit/issues/147) for details.
 
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