rspec: add page (#4614)

pages/common/rspec.md

@@ -0,0 +1,32 @@
+# rspec
+
+> Behavior-driven development testing framework written in Ruby to test Ruby code.
+> More information: <https://rspec.info>.
+
+- Initialise an .rspec config and a spec helper file:
+
+`rspec --init`
+
+- Run all tests:
+
+`rspec`
+
+- Run a specific directory of tests:
+
+`rspec {{path/to/directory}}`
+
+- Run a specific test file:
+
+`rspec {{path/to/file}}`
+
+- Run multiple test files:
+
+`rspec {{path/to/file1}} {{path/to/file2}}`
+
+- Run a specific test in a file (e.g. the test starts on line 83):
+
+`rspec {{path/to/file}}:{{83}}`
+
+- Run specs with a specific seed:
+
+`rspec --seed {{seed_number}}`