Amend ruby version in docker image and documentation (#750)

Author: haydenrou

README.md

@@ -13,7 +13,7 @@ Help would be appreciated! Please join us in [slack #flaredown](https://rubyforg
 * PostgreSQL 12.8
 * MongoDB 4.4.9
 * Redis 6.2.3
-* Ruby 3.1.3
+* Ruby 3.2.3
 * Node 12.22.6
 
 ## Installation

backend/Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:3.1.3
+FROM ruby:3.2.3
 
 # set working directory
 WORKDIR /app

backend/Gemfile

@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-ruby file: ".ruby-version"
+ruby "3.2.3"
 
 # Configuration management. keep on top of Gemfile
 gem "dotenv-rails", groups: %i[development test]