feat: add complementary description to exploration

src/components/Challenge/ChallengeCard.spec.tsx

...nents/Challenge/__snapshots__/ChallengeCard.spec.tsx.snap

...nents/Challenge/__snapshots__/ChallengeView.spec.tsx.snap

src/components/Exploration/ExplorationOngoing.spec.tsx

src/components/Exploration/ExplorationOngoing.tsx

src/components/Exploration/explorationOngoing.scss

src/db/explorationEntity.json

src/models/exploration.model.ts

src/services/exploration.service.ts

test/__mocks__/explorationData.mock.ts

test/__mocks__/userChallengeData.mock.ts