nvm, poetry, pyenv, rbenv: add asdf to see also section (#12034)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

pages/common/nvm.md

@@ -2,6 +2,7 @@
 
 > Install, uninstall or switch between Node.js versions.
 > Supports version numbers like "12.8" or "v16.13.1", and labels like "stable", "system", etc.
+> See also: `asdf`.
 > More information: <https://github.com/creationix/nvm>.
 
 - Install a specific version of Node.js:

pages/common/poetry.md

@@ -1,6 +1,7 @@
 # poetry
 
 > Manage Python packages and dependencies.
+> See also: `asdf`.
 > More information: <https://python-poetry.org/docs/cli/>.
 
 - Create a new Poetry project in the directory with a specific name:

pages/common/pyenv.md

@@ -1,6 +1,7 @@
 # pyenv
 
 > Switch between multiple versions of Python easily.
+> See also: `asdf`.
 > More information: <https://github.com/pyenv/pyenv>.
 
 - List all available commands:

pages/common/rbenv.md

@@ -1,6 +1,7 @@
 # rbenv
 
 > A tool to easily install Ruby versions and manage application environments.
+> See also: `asdf`.
 > More information: <https://github.com/rbenv/rbenv>.
 
 - Install a Ruby version: