Question #$3$ Full ER Diagram: A software development consulting company is creating a new database to track their consulting projects based on the following design requirements:$$

There are $3$ types of employees in the consulting company: project manager, developer, and UI$/$UX designer. Each employee is one of these types. Every employee has a name $($first and last$),$ a unique company email, and a salary.$$ The database maintains a developer's github username $($unique$),$ experience level $($entry$-$level, junior, senior, principal$),$ and $1$ or more programming languages in which they are proficient.$$

Every UI$/$UX designer consults with a single project manager in the company on all their designs. Not all managers will have a UI$/$UX designer because they may only work on backend projects.

Customers are identified by their company name and the state in which they reside. Each customer has contact information, that includes a company contact name $($first and last$)$ and phone number. They can also include email addresses.$$

When a company signs a contract for a specific project, the project is assigned a project number specific to the company.$$ The total budget for the project is specified. For billing purposes, the combined number of developers and managers who worked on the project over its duration is tracked.$$

Every project is assigned $1$ manager to oversee the project. The total number of projects currently assigned to each manager is stored.$$

Each project requires at least one developer. Developers are assigned to multiple projects at a time based on their experience level and the programming languages that they know, but no more than $3$ projects at a time. The date $($month and year$)$ the developer starts and ends on a project is tracked.

A developer can be mentored by at most $1$ other developer, but a developer can be a mentor to many.$$

Based on the description above, draw the complete E$-$R diagram.