Add ruby arrays notes

src/SUMMARY.md

@@ -12,6 +12,8 @@
   - [Rust](./dev/rust/main.md)
     - [serde](./dev/rust/serde.md)
     - [Testing](./dev/rust/testing.md)
+  - [Ruby](./dev/ruby/main.md)
+    - [arrays](./dev/ruby/arrays.md)
   - [Web](./dev/web/main.md)
     - [front](./dev/web/front/main.md)
       - [babel and babel-preset-stage-2](./dev/web/front/babel-preset-stage-2.md)

src/dev/ruby/arrays.md

@@ -0,0 +1,6 @@
+# Check if all array elements are equals
+
+```ruby
+arr = [0, 0, 0, 0, 0, 0, 0]
+puts true if arr.uniq.length == 1
+```

src/dev/ruby/main.md

@@ -0,0 +1 @@
+# Ruby