phpenv: add page (#2721)

pages/common/phpenv.md

@@ -0,0 +1,31 @@
+# phpenv
+
+> A PHP version manager for development purposes.
+
+- Install a PHP version globally:
+
+`phpenv install {{version}}`
+
+- Refresh shim files for all PHP binaries known to `phpenv`:
+
+`phpenv rehash`
+
+- List all installed PHP versions:
+
+`phpenv versions`
+
+- Display the currently active PHP version:
+
+`phpenv version`
+
+- Set the global PHP version:
+
+`phpenv global {{version}}`
+
+- Set the local PHP version, which overrides the global version:
+
+`phpenv local {{version}}`
+
+- Unset the local PHP version:
+
+`phpenv local --unset`