my plugin is not showing in th plugins menu

The install instructions (the ones you have, but not formatted in notepad) :

"Instructions WP:
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1) Place the membership directory in the plugins directory
2) Activate the plugin

Instructions WPMU:
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1) Place the membership.php file in the mu-plugins directory
2) Place the membershipincludes in the mu-plugins directory

Alternatively, follow instructions for WP and activate sitewide."

they look so much clearer here.

So I followed these instructions and I don't see the plugin in the plugins list.