Now you can also keep attachments on projects.
To configure it, firstly you need to create a custom field on the Project object.
Click on Setup.
Under Administer section expand Create options and choose Objects.
On the list of Precursive objects choose the Project object.
In the Custom Fields & Relationships section click on the New button to create the Attachment custom field. It should be a Long Text Area field with API name attachment__c
When the Attachment field is created, you can add it to the Project or Project Phase layout, just remember to add it as an Attachment type.
If you don't know how to do add a custom field to the Project or Phase layout, follow the article below:
Remark: The maximum size of files attached to a project can't be bigger than 1,5 MB per single upload!