New `allEmojis()` method, improve parser and tests

• New allEmojis() method to get all emojis of the input string.
• Improved Unicode parser.
• New tests.

New `startingEmojis()` method, simple tests

• New startingEmojis() method to get starting emojis of the input string.
• Add simple tests.

New Emojis, Unicode 14.0 → 15.0, PHP 8.2

• New Emojis: 🫨, 🩷, 🩵, 🩶, 🫸, 🫷, 🫎, 🫏, 🪼, etc (see https://unicode.org/emoji/charts-15.0/emoji-released.html for full list of recently added symbols)
• Unicode version updated from 14.0 to 15.0
• PHP 8.2 support

New Emojis, Unicode 13.1→14.0

• New Emojis: 🫠, 🫣, 🫥, 🫰, 🫵, 🫃, 🧌, 🪬, 🩼, etc (see https://unicode.org/emoji/charts-14.0/emoji-released.html for full list of recently added symbols)
• Unicode version updated from 13.1 to 14.0

Add PHP 8.0 and 8.1 support to dependencies

Version 1.3 resolves the corresponding issue #1.

New Emojis, Unicode 13.0→13.1

• New Emojis: ❤️‍🔥, ❤️‍🩹, 🧔‍♀️, 🧔‍♂️, 😮‍💨, 😶‍🌫️, 😵‍💫
• Unicode version updated from 13.0 to 13.1
• Make parser to update Unicode version in README file

New Emojis, Unicode 12.1→13.0

• New Emojis
• Unicode version updated from 12.1 to 13.0
• Add .editorconfig