README.md in percy-common-1.1.0 vs README.md in percy-common-1.2.0

@@ -1,3 +1,99 @@
 # percy-common
 
 Server-side common library for Percy.
+
+## Percy::KeywordStruct
+
+A simple struct that can be used when you need to return a simple value object.
+
+```ruby
+require 'percy/keyword_struct'
+
+class Foo < Percy::KeywordStruct.new(:bar, :baz, :qux)
+end
+
+foo = Foo.new(bar: 123, baz: true)
+foo.bar  # --> 123
+foo.baz  # --> true
+foo.qux  # --> nil
+foo.fake # --> raises NoMethodError
+```
+
+## Percy.logger
+
+```ruby
+require 'percy/logger'
+
+Percy.logger.debug { 'debug log' }
+Percy.logger.info { 'info log' }
+Percy.logger.warn { 'warning log' }
+Percy.logger.error { 'error message' }
+```
+
+Prefer the block form usage `Percy.logger.debug { 'message' }` over `Percy.logger.debug('message')` because it is slightly more efficient when the log will be excluded by the current logging level. For example, if the log level is currently `info`, then a `debug` log in block form will never evaluate or allocate the message string itself.
+
+## Percy::ProcessHelpers
+
+### `gracefully_kill(pid[, grace_period_seconds: 10])`
+
+Returns `true` if the process was successfully killed, or `false` if the process did not exist or its exit status was already collected.
+
+```ruby
+require 'percy/process_helpers'
+
+Percy::ProcessHelpers.gracefully_kill(pid)
+```
+
+This will send `SIGTERM` to the process, wait up to 10 seconds, then send `SIGKILL` if it has not already shut down.
+
+## Percy::Stats
+
+Client for recording Datadog metrics and automatically setting up Percy-specific environment tags.
+
+This class is a wrapper for [Datadog::Statsd](https://github.com/DataDog/dogstatsd-ruby), an extended client for DogStatsD, which extends the StatsD metric server for Datadog.
+
+Basic usage includes:
+
+```ruby
+require 'percy/stats'
+
+stats = Percy::Stats.new
+
+# Increment a counter.
+stats.increment('page.views')
+
+# Record a gauge 50% of the time.
+stats.gauge('users.online', 123, sample_rate: 0.5)
+
+# Sample a histogram.
+stats.histogram('file.upload.size', 1234)
+
+# Time a block of code.
+stats.time('page.render') do
+  render_page('home.html')
+end
+
+# Send several metrics at the same time.
+# All metrics will be buffered and sent in one packet when the block completes.
+stats.batch do |s|
+  s.increment('page.views')
+  s.gauge('users.online', 123)
+end
+
+# Tag a metric.
+stats.histogram('query.time', 10, tags: ['version:1'])
+```
+
+See the [Datadog::Statsd](https://github.com/DataDog/dogstatsd-ruby) docs for more usage.
+
+Our wrapper adds support for a non-block based `start_timing` and `stop_timing` methods:
+
+```ruby
+require 'percy/stats'
+
+stats = Percy::Stats.new
+
+stats.start_timing
+account.activate!
+stats.stop_timing('account.activate')
+```