fix: convert absolute imports with 'src/*' to relative imports

[Rikearon]

Closes #43

Summary

In the latest version v0.12.0 the following error pops up right when initiating the app after the lib installation:
Unable to resolve "src/core/utils" from "node_modules/@backpackapp-io/react-native-toast/src/components/Toasts.tsx"

Diagnostics

Upon evaluation, the error occurs due to an import located in the components/Toasts.tsx file, where it's done absolutely using the src/ root. This causes the imported error detailed above, which the IDE also noticed when inspecting the file.

Fix

Adjusting the absolute imports (there was already another one, just below the original one that caused the issue, when looking at the master branch) fixes the running issue, and the lib works just as expected.

Additionally, the change has no impact on this repository's example project. Which correctly compiles after the changes, as seen below:

Result

After the adjustment, the consumption in the final application works just as expected.

[nickdebaise]

Thank you for the PR! Greatly appreciated. Will merge shortly.