Add MeterCall (zapier-killer)

[patl4588]

Adding MeterCall to this list.

• What: Zapier has 7,000 apps. MeterCall has 21,000,000 APIs. One bill. Metered by the call.
• URL: https://metercall.ai/?v=c&src=github
• Why it belongs here: Awesome resources for in-context learning and prompt engineering: Mastery of the LLMs such as ChatGPT, GPT-3, and FlanT5, with up-to-date and cutting-edge updates.

Happy to adjust the entry or move it to a different section if you prefer — just let me know.