update README

Author: lbarulski

README.md

@@ -1 +1,44 @@
-# github-flow-manager
+# github-flow-manager
+## Help
+```
+Main goal for that app is to push commits between branches
+but just those which pass evaluation checks.
+Example use case "push all commits pushed to branch develop more than 30 minutes ago to branch master"
+
+Usage:
+  github-flow-manager [OWNER] [REPOSITORY] [SOURCE_BRANCH] [DESTINATION_BRANCH] [EXPRESSION] [flags]
+
+Flags:
+  -c, --commits-number int    Number of commits to get under evaluation (>0, <=100) (default 100)
+  -d, --dry-run               Don't modify repository
+  -f, --force                 Use the force Luke... - Changes branch HEAD with force
+  -t, --github-token string   GitHub token (can be passed also as GITHUB_TOKEN env variable
+  -h, --help                  help for github-flow-manager
+  -v, --verbose               Print table with commits evaluation status
+```
+
+## Example
+```
+GITHUB_TOKEN=xxx github-flow-manager octocat Hello-World test master "StatusSuccess == false" --verbose --dry-run
+```
+
+# Expressions
+### Available variables
+ - `SHA`
+ - `Message`
+ - `PushedDate` - when commit was pushed
+ - `StatusSuccess` - f.ex. CI status
+
+### Examples
+##### Commit message contains "string"
+`Message contains "HOTFIX"`
+##### Commit message not contains "string"
+`Message NOT contains "FEATURE"`
+##### Commit message equals "string"
+`Message == "very important commit"`
+##### Commit status is SUCCESS
+`StatusSuccess == true`
+##### Commit was pushed more than 30 minutes ago
+`PushedDate < "now-30m"`
+##### Commit was pushed more than 30 minutes ago and status is SUCCESS
+`PushedDate < "now-30m" AND StatusSuccess == true`