Inform users on location of iii-cli if iii-cli is already in PATH

[anthonyiscoding]

If a user installs iii and then tries to install to a different path they will get a message saying iii is already installed. This is good but can be more informative and should show the user where it's currently installed and tell them to remove it first if they'd like to install iii-cli to another location.

~/motia/projects/iii-docs chore/docs-revision ❯ curl -fsSL https://install.iii.dev/iii-cli/main/install.sh | bash -s -- -v 0.2.4
Installed version: 0.2.3. Upgrading...
Installing iii-cli version: 0.2.4

Downloading iii-cli v0.2.4
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Checksum verified

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Get started:

  iii-cli console          # Launch iii-console
  iii-cli create           # Create new project
  iii-cli motia            # Run motia CLI
  iii-cli --help           # See all commands

Installed to: /Users/tony/.local/bin/iii-cli


~/motia/projects/iii-docs chore/docs-revision ❯ mkdir ~/.test
~/motia/projects/iii-docs chore/docs-revision ❯ curl -fsSL https://install.iii.dev/iii-cli/main/install.sh | INSTALL_DIR=~/.test bash
Installing iii-cli latest version
Version 0.2.4 already installed
~/motia/projects/iii-docs chore/docs-revision ❯ ls ~/.test/