Add Workflow For Spell-Checking

[O957]

This PR:

• Fixes spelling errors (only 1) found across pyalex.
• Adds a workflow called fix-typos.yaml to ./.github/workflows that runs in pulls requests and checks for common spelling mistakes.
• Adds the hook for typos in the .pre-commit-config.yaml file.
• Adds a configuration file (_typos.yaml), which can be used for false positives, for the typos workflow.

If interested in this PR, please choose between the pre-commit hook and the workflow.

Example Error Found Using Typos In Pre-Commit (Locally)

One can use _typos.toml to indicate false positives (this doesn't seem to be needed in pyalex right now, but it's good to have). For example,

Example Typos Configuration File