Monthly goals integration, plus improvements

app/controllers/goals_controller.rb

app/controllers/habits_controller.rb

app/helpers/goals_helper.rb

app/models/goals.rb

app/views/goals/_goals.html.erb

app/views/goals/_showgoals.html.erb

app/views/goals/completed.html.erb

app/views/goals/createBaseGoals.html.erb

app/views/goals/createHabitGoals.html.erb

app/views/goals/index.html.erb

config/routes.rb

db/migrate/20210429192435_add_habit_id_to_goals.rb

db/schema.rb