Proposing a PR to fix a few small typos

[timgates42]

Issue Type

[x] Bug (Typo)

Steps to Replicate and Expected Behaviour

• Examine tornadio2/persistent.py, tornadio2/session.py and observe hearbeat, however expect to see heartbeat.
• Examine doc/deployment.rst and observe writting, however expect to see writing.
• Examine examples/socket.io.js and observe trigged, however expect to see triggered.
• Examine examples/socket.io.js and observe publci, however expect to see public.
• Examine doc/bugs.rst and observe parametes, however expect to see parameters.
• Examine tornadio2/polling.py and observe hearbeats, however expect to see heartbeats.
• Examine examples/socket.io.js and observe corss, however expect to see cross.
• Examine examples/socket.io.js and observe costructor, however expect to see constructor.

Notes

Semi-automated issue generated by
https://github.com/timgates42/meticulous/blob/master/docs/NOTE.md

To avoid wasting CI processing resources a branch with the fix has been
prepared but a pull request has not yet been created. A pull request fixing
the issue can be prepared from the link below, feel free to create it or
request @timgates42 create the PR. Alternatively if the fix is undesired please
close the issue with a small comment about the reasoning.

https://github.com/timgates42/tornadio2/pull/new/bugfix_typos

Thanks.