docs: add README.md for project setup and usage

chore: add .env.example for environment configuration

feat: add environment variable handling with Zod validation

fix: handle null check for goalsPerDay before mapping

feat: add handleCreateGoal function to submit form data and create goal

feat: install react-hook-form and @hookform/resolvers, create form for CreateGoal

feat: add handleCompletionGoal function, call API on goal completion and invalidate queries to reload data

feat: create pending-goals component, fetch and render pending goals from API

feat: install dayjs and @tanstack/react-query, render completed goals of the week

feat: create summary page component

Refactor: separate DialogCreateGoal and EmptyGoals components for reuse

Feat: add dialog on 'cadastrar meta' button click

Feat: create first page and components

initial commit