doc: Add misc links, improve wording

doc/rtd/explanation/analyze.rst

@@ -3,15 +3,18 @@
 Performance
 ***********
 
-The :command:`analyze` subcommand was added to ``cloud-init`` to help analyze
-``cloud-init`` boot time performance. It is loosely based on
-``systemd-analyze``, where there are four subcommands:
+The :command:`analyze` subcommand helps to analyze ``cloud-init`` boot time
+performance. It is loosely based on ``systemd-analyze``, where there are four
+subcommands:
 
 - :command:`blame`
 - :command:`show`
 - :command:`dump`
 - :command:`boot`
 
+The analyze subcommand works by parsing the cloud-init log file for timestamps
+associated with specific events.
+
 Usage
 =====
 

doc/rtd/explanation/events.rst

@@ -66,9 +66,10 @@ Hotplug
 =======
 
 When the ``hotplug`` event is supported by the datasource and configured in
-user data, ``cloud-init`` will respond to the addition or removal of network
-interfaces to the system. In addition to fetching and updating the system
-metadata, ``cloud-init`` will also bring up/down the newly added interface.
+:ref:`user data<mod_cc_install_hotplug>`, ``cloud-init`` will respond to the
+addition or removal of network interfaces to the system. In addition to
+fetching and updating the system metadata, ``cloud-init`` will also bring
+up/down the newly added interface.
 
 .. warning::
    Due to its use of ``systemd`` sockets, ``hotplug`` functionality is

doc/rtd/explanation/format.rst

@@ -5,7 +5,9 @@ User data formats
 
 User data is configuration data provided by a user of a cloud platform to an
 instance at launch. User data can be passed to cloud-init in any of many
-formats documented here.
+formats documented here. User data is combined with the other
+:ref:`configuration sources<configuration>` to create a combined configuration
+which modifies an instance.
 
 Configuration types
 ===================
@@ -385,6 +387,11 @@ as binary data and so may be processed automatically.
 |Part handler        |#part-handler                |text/part-handler        |
 +--------------------+-----------------------------+-------------------------+
 
+Continued reading
+=================
+
+See the :ref:`configuration sources<configuration>` documentation for
+information about other sources of configuration for cloud-init.
 
 .. _make-mime: https://github.com/canonical/cloud-init/blob/main/cloudinit/cmd/devel/make_mime.py
 .. _YAML: https://yaml.org/spec/1.1/current.html

doc/rtd/explanation/instancedata.rst

@@ -65,7 +65,6 @@ Using ``instance-data``
 
 ``instance-data`` can be used in:
 
-* :ref:`User data scripts<user_data_script>`.
 * :ref:`Cloud-config data<user_data_formats>`.
 * :ref:`Base configuration<configuration>`.
 * Command line interface via :command:`cloud-init query` or

doc/rtd/explanation/introduction.rst

@@ -113,6 +113,6 @@ and how it works, you will probably want to
 
 You can also read in more detail about what cloud-init does
 :ref:`during the different boot stages<boot_stages>`, and the
-:ref:`types of configuration<configuration>` you can pass to cloud-init and
+:ref:`types of configuration<user_data_formats>` you can pass to cloud-init and
 how they're used.
 

doc/rtd/explanation/kernel-command-line.rst

@@ -2,18 +2,12 @@ Kernel command line
 *******************
 
 Providing configuration data via the kernel command line is somewhat of a last
-resort, since this method only supports
-:ref:`cloud config<user_data_formats-cloud_config>` starting with
-`#cloud-config`, and many datasources do not support injecting kernel
-command line arguments without modifying the bootloader.
-
-Despite the limitations of using the kernel command line, cloud-init supports
-some use-cases.
+resort, since many datasources do not support injecting kernel command line
+arguments without modifying the bootloader.
 
 Note that this page describes kernel command line behavior that applies
-to all clouds. To provide a local configuration with an image using kernel
-command line, see :ref:`datasource NoCloud<datasource_nocloud>` which provides
-more configuration options.
+to all clouds. The :ref:`NoCloud datasource<datasource_nocloud>` provides more
+configuration options.
 
 .. _kernel_datasource_override:
 

doc/rtd/explanation/vendordata.rst

@@ -29,9 +29,10 @@ Input formats
 =============
 
 ``Cloud-init`` will download and cache to filesystem any vendor data that it
-finds. Vendor data is handled exactly like user data. This means that the
-vendor can supply multi-part input and have those parts acted on in the same
-way as with user data.
+finds. Vendor data is handled exactly like
+:ref:`user data<user_data_formats>`. This means that the vendor can supply
+multi-part input and have those parts acted on in the same way as with user
+data.
 
 The only differences are:
 

doc/rtd/reference/datasources/vmware.rst

@@ -389,7 +389,7 @@ this datasource using the GuestInfo keys transport:
 
    Otherwise ``cloud-init`` may not run in first-boot mode. For more
    information on how the boot mode is determined, please see the
-   :ref:`First Boot Documentation <boot-First_boot_determination>`.
+   :ref:`first boot documentation <First_boot_determination>`.
 
    .. raw:: html