Add tags to challenges 81-100

[kevmoens]

On each challenge there is a property named Tags.

        private Dictionary<string, string> _tags = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase) { {"Math","Add"}, { "Level", "1" } };
        public Dictionary<string, string> Tags { get => _tags; set => _tags = value; }

Tags describe the type of coding being done in each challenge.
In the code above is describing the challenge uses Math to Add and Level is 1.
You can add as many tags as you like to help describe the challenge.
Add a Level tag to each challenge.
Currently levels are described as:
Level 1 = beginner concept
Level 2 = Use of beginner concept with more detailed knowledge to code
Level 3 = Something that requires in depth knowledge to code
Level 4 = This is a complex challenge that will take more than 10 minutes to code for an advanced developer
Level 5 = This is a senior developer that will take more than 15-20 minutes to code

[kevmoens]

fixed by #36