Document missing server config options

docs/usage/configuration/config_documentation.md

@@ -162,6 +162,53 @@ Example configuration:
 pid_file: DATADIR/homeserver.pid
 ```
 ---
+### `daemonize`
+
+Specifies whether Synapse should be started as a daemon process. If Synapse is being
+managed by [systemd](../../systemd-with-workers/), this option must be omitted or set to
+`false`.
+
+This can also be set by the `--daemonize` (`-D`) argument when starting Synapse.
+
+See [`worker_daemonize`](TODO) for more information on daemonizing workers.
+
+Example configuration:
+```yaml
+daemonize: true
+```
+---
+### `print_pidfile`
+
+Print the path to the pidfile just before daemonizing. Defaults to false.
+
+This can also be set by the `--print-pidfile` argument when starting Synapse.
+
+Example configuration:
+```yaml
+print_pidfile: true
+```
+---
+### `user_agent_suffix`
+
+A suffix that is appended to the Synapse user-agent (ex. `Synapse/v1.123.0`). Defaults
+to None
+
+Example configuration:
+```yaml
+user_agent_suffix: " (I'm a teapot; Linux x86_64)"
+```
+---
+### `use_frozen_dicts`
+
+Determines whether we should freeze the internal dict object in `FrozenEvent`. Freezing
+prevents bugs where we accidentally share e.g. signature dicts. However, freezing a
+dict is expensive. Defaults to false.
+
+Example configuration:
+```yaml
+use_frozen_dicts: true
+```
+---
 ### `web_client_location`
 
 The absolute URL to the web client which `/` will redirect to. Defaults to none.
@@ -595,6 +642,15 @@ listeners:
       - names: [client, federation]
 ```
 
+---
+### `manhole`
+
+Turn on the Twisted telnet manhole service on the given port. Defaults to none.
+
+Example configuration:
+```yaml
+manhole: 1234
+```
 ---
 ### `manhole_settings`
 

synapse/events/__init__.py

@@ -22,7 +22,7 @@
 
 import abc
 import collections.abc
 import os
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -48,21 +48,22 @@
 from synapse.types import JsonDict, StrCollection
 from synapse.util.caches import intern_dict
 from synapse.util.frozenutils import freeze
 from synapse.util.stringutils import strtobool
 
 if TYPE_CHECKING:
     from synapse.events.builder import EventBuilder
 
-# Whether we should use frozen_dict in FrozenEvent. Using frozen_dicts prevents
-# bugs where we accidentally share e.g. signature dicts. However, converting a
-# dict to frozen_dicts is expensive.
-#
-# NOTE: This is overridden by the configuration by the Synapse worker apps, but
-# for the sake of tests, it is set here while it cannot be configured on the
-# homeserver object itself.
 
-USE_FROZEN_DICTS = strtobool(os.environ.get("SYNAPSE_USE_FROZEN_DICTS", "0"))
+USE_FROZEN_DICTS = False
+"""
+Whether we should use frozen_dict in FrozenEvent. Using frozen_dicts prevents
+bugs where we accidentally share e.g. signature dicts. However, converting a
+dict to frozen_dicts is expensive.
 
+NOTE: This is overridden by the configuration by the Synapse worker apps, but
+for the sake of tests, it is set here because it cannot be configured on the
+homeserver object itself.
+"""
 
 T = TypeVar("T")