message: fix a couple typos
  a, uh, friend of mine, copied the url over when configuring and it unfortunately had the misspelled version of `receive`
diff: @@ -512,7 +512,7 @@ This url should be used when configuring Slack.
  When a slash command is received from Slack, Botkit fires the `slash_command` event.
  -When an outgoing webhook is recieved from Slack, Botkit fires the `outgoing_webhook` event.
  +When an outgoing webhook is received from Slack, Botkit fires the `outgoing_webhook` event.
  #### bot.replyAcknowledge
  @@ -919,7 +919,7 @@ Developers may want to create an RTM connection in order to make the bot appear
  1. Create a [Slack App](https://api.slack.com/apps/new)
  2. Setup oauth url with Slack so teams can add your app with the slack button. Botkit creates an oAuth endpoint at `http://MY_HOST/oauth` if using localtunnel your url may look like this `https://example-134l123.localtunnel.me/oauth`
  -3. Setup request URL under Events API to receive events at. Botkit will create webhooks for slack to send messages to at `http://MY_HOST/slack/recieve`. if using localtunnel your url may look like this `https://example-134l123.localtunnel.me/slack/receive`
  +3. Setup request URL under Events API to receive events at. Botkit will create webhooks for slack to send messages to at `http://MY_HOST/slack/receive`. if using localtunnel your url may look like this `https://example-134l123.localtunnel.me/slack/receive`
  4. Select the specific events you would like to subscribe to with your bot. Slack only sends your webhook the events you subscribe to. Read more about Event Types [here](https://api.slack.com/events)
  5. When running your bot, you must configure the slack app, setup webhook endpoints, and oauth endpoints.
  