docs: fix 13 typos and grammar errors in comments and documentation

[Avicennasis]

Summary

Fix 13 typos and grammar errors across 5 files.

docs/interactions/web-messaging/source.md

• Here is an example that specify the rendering → Here is an example that specifies the rendering
• found on thepage → found on the page
• place their agents on the spotlight → place their agents in the spotlight
• The integrations reports the following events → The integrations report the following events
• the total number of slotswould be 10 → the total number of slots would be 10
• corresponding to an unit → corresponding to a unit
• translations on many languages → translations in many languages

docs/interactions/web-messaging/javascript-api.md

• a chat client that reopens himself after a page change → a chat client that reopens itself after a page change

docs/interactions/structured-messages/apple-auth.md

• The authenticate field is juste the replication → The authenticate field is just the replication

docs/interactions/structured-messages/select.md

• for you own custom images → for your own custom images
• Booelan → Boolean

docs/sdks/source-sdk/send-api.md

• params key content depends to the action→params key content depends on the action
• A mandatort contents attribute is missing → A mandatory contents attribute is missing

Comments, documentation and message strings only — no functional changes.