README update to include flutter, and pubdev badge

[gabrielbmoro]

Description

Add pubdev + flutter badges

Screenshots

Check list

• The tests were executed and passed successfully.
• Code changes follow the project style guidelines.
• Tests have been added if applicable.
• Did you subscribe to the channel?😛

Related Issues

• Closes pubdev badge #66

[github-actions]

🦙 MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
⚠️ KOTLIN	detekt	yes		139	no	4.18s
⚠️ MARKDOWN	markdown-table-formatter	20		1	0	0.34s
⚠️ YAML	prettier	16		1	3	0.9s

See detailed report in MegaLinter reports

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