Add IgboSpeech navigation option in nav bar

[ijemmao]

Is your feature request related to a problem? Please describe.
Nope, this is a feature request. We want to make the IgboSpeech more discoverable from the Igbo API website.

Describe the solution you'd like
Add "IgboSpeech" navigation option directly to the right of the "Research" option in the Igbo API navigation bar. The link should point to the IgboSpeech website: https://speech.igboapi.com.

Make sure to update existing tests to check for IgboSpeech. At least two test files should be updated after making this change.

Describe alternatives you've considered
N/A

Additional context
Ideal location for inserting IgboSpeech

[vickywane]

@ijemmao I would love to work on this.

[ijemmao]

@vickywane all yours!

(other people are able to attempt this ticket as well)