message: Fix mistakes in contribution guide
diff: @@ -34,14 +34,14 @@ env PACKAGE_OUTPUT_PATH="$(pwd)/../PATH-TO-YOUR-MODULE/node_modules/date-fns" ./
  ## Adding a new function
  -In order to add a new function, first you should is name.
  +In order to add a new function, first you should choose its name.
  The functions are named in camelCase. The following rules apply:
  -- If the function returns a modified date, the name should be a verb (`addDays`, `setDay`, ...)
  -- If the function takes some value from a date, its name should start with `get` (`getDaysInYear`, ...)
  +- If the function returns a modified date, the name should be a verb (`addDays`, `setDay`, ...).
  +- If the function takes some value from a date, its name should start with `get` (`getDaysInYear`, ...).
  - If the function returns a new date somehow calculated from another date,
  - its name should be a noun (`lastDayOfMonth`, `startOfDay`, ...)
  + its name should be a noun (`lastDayOfMonth`, `startOfDay`, ...).
  - For the consistency with the standard JavaScript library,
  - `date` in the name refers to the day of month. `toDate` is an exception
  + `date` in the name refers to the day of month. `toDate` is an exception of this rule.
  - For similar reasons, `day` in the name refers to the day of the week.
  Create a directory `src/yourFunction` and files `src/yourFunction/index.js` and `src/yourFunction/test.js`.
  