Grammar, spelling on README; Codeblock formatting [ci skip]

- LinkedIn item missing link to issue, rendering the rest of the
  line as broken link
- Codeblocks in lists need to indent four spaces for each nesting
  under bullet list item
- Fix some capitalisation in certain words
- Some paragraphs work better with multiple sentences instead
  of using many commas
Add login form to nav bar

When user clicks on "Login" on nav menu, a small form will appear
that will allow the user to enter their email & password and log
into the site.

By default the mini login form will not show.

Closes #282
Merge pull request #317 from randomecho/copyedit-readme

Copyedits on README - Codeblock formatting, grammar and fixing a link to issue
Merge pull request #318 from randomecho/282-login-form-on-nav-bar

Add login form to nav bar
fix:security
Merge pull request #319 from albanlv/master

fix:security
Button "Edit place" on the place page
Remove ruby from Gemfile

If we have ruby version on .ruby-version no need to have it on Gemfile too
Move rvmrc to .ruby-gemset
Remove double gem definition of hominid
Merge pull request #321 from arthurnn/ci

Remove ruby from Gemfile
Merge pull request #322 from arthurnn/rvmrv

Move rvmrc to .ruby-gemset
Merge pull request #320 from nikitachernov/master

Button "Edit place" on the place page
Merge pull request #323 from arthurnn/hominid

Remove double gem definition of hominid
improv: update and simplify dependencies

Update gems. Move to Ruby 2.0

[3:00]
fix: remove buggy Facebook integration

[0:30]