docs: Add initial language settings documentation (#6957)

This pull request implements the following documentation changes:

- [x] Copy existing language settings docs from old docs repo
- [x] Add new pages for Zig, Haskell, Gleam, Deno and PureScript
- [x] Add `rust-analyzer` target directory section to Rust language page

Release Notes:

- Added initial language settings documentation
([#4264](https://github.com/zed-industries/zed/issues/4264)).

docs/src/languages/python.md

@@ -0,0 +1,60 @@
+# Python
+
+- Tree Sitter: [tree-sitter-python](https://github.com/tree-sitter/tree-sitter-python)
+- Language Server: [pyright](https://github.com/microsoft/pyright)
+
+### Configuration
+
+The [pyright](https://github.com/microsoft/pyright) language server offers flexible configuration options specified in a JSON-formatted text configuration. By default, the file is called `pyrightconfig.json` and is located within the root directory of your project. Pyright settings can also be specified in a `[tool.pyright]` section of a `pyproject.toml` file. A `pyrightconfig.json` file always takes precedent over `pyproject.toml` if both are present.
+
+For more information, see the Pyright [configuration documentation](https://microsoft.github.io/pyright/#/configuration).
+
+### Virtual environments
+
+A python [virtual environment](https://docs.python.org/3/tutorial/venv.html) allows you to store all of a project's dependencies, including the Python interpreter and package manager, in a single directory that's isolated from any other Python projects on your computer.
+
+By default, the Pyright language server will look for Python packages in the default global locations. But you can also configure Pyright to use the packages installed in a given virtual environment.
+
+To do this, create a JSON file called `pyrightconfig.json` at the root of your project. This file must include two keys:
+
+* `venvPath`: a relative path from your project directory to any directory that _contains_ one or more virtual environment directories
+* `venv`: the name of a virtual environment directory
+
+For example, a common approach is to create a virtual environment directory called `.venv` at the root of your project directory with the following commands:
+
+```bash
+# create a virtual environment in the .venv directory
+python3 -m venv .venv
+# set up the current shell to use that virtual environment
+source .venv/bin/activate
+```
+
+Having done that, you would create a `pyrightconfig.json` with the following content:
+
+```json
+{
+  "venvPath": ".",
+  "venv": ".venv"
+}
+```
+
+### Code formatting
+
+The Pyright language server does not provide code formatting. If you want to automatically reformat your Python code when saving, you'll need to specify an _external_code formatter in your settings. See the [configuration](../configuration/configuring-zed.md) documentation for more information.
+
+A common tool for formatting python code is [Black](https://black.readthedocs.io/en/stable/). If you have Black installed globally, you can use it to format Python files by adding the following to your `settings.json`:
+
+```json
+{
+  "language_overrides": {
+    "Python": {
+      "format_on_save": {
+        "external": {
+          "command": "black",
+          "arguments": ["-"]
+        }
+      }
+    }
+  }
+}
+```