binman: doc: Add documentation to htmldocs

Add a link to binman's documentation and adjust the files so that it is
accessible. Use the name README.rst so it is easy to discover when binman
is installed without U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/develop/index.rst b/doc/develop/index.rst
index 444df67..3edffbc 100644
--- a/doc/develop/index.rst
+++ b/doc/develop/index.rst
@@ -26,6 +26,14 @@
    crash_dumps
    trace
 
+Packaging
+---------
+
+.. toctree::
+   :maxdepth: 1
+
+   package/index
+
 Testing
 -------
 
diff --git a/doc/develop/package/binman.rst b/doc/develop/package/binman.rst
new file mode 120000
index 0000000..2e26e84
--- /dev/null
+++ b/doc/develop/package/binman.rst
@@ -0,0 +1 @@
+../../../tools/binman/binman.rst
\ No newline at end of file
diff --git a/doc/develop/package/index.rst b/doc/develop/package/index.rst
new file mode 100644
index 0000000..9374be2
--- /dev/null
+++ b/doc/develop/package/index.rst
@@ -0,0 +1,19 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Package U-Boot
+==============
+
+U-Boot uses Flat Image Tree (FIT) as a standard file format for packaging
+images that it it reads and boots. Documentation about FIT is available at
+doc/uImage.FIT
+
+U-Boot also provides binman for cases not covered by FIT. Examples include
+initial execution (since FIT itself does not have an executable header) and
+dealing with device boundaries, such as the read-only/read-write separation in
+SPI flash.
+
+
+.. toctree::
+   :maxdepth: 2
+
+   binman
diff --git a/doc/usage/fit.rst b/doc/usage/fit.rst
new file mode 100644
index 0000000..7037434
--- /dev/null
+++ b/doc/usage/fit.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Flat Image Tree (FIT)
+=====================
+
+U-Boot uses Flat Image Tree (FIT) as a standard file format for packaging
+images that it it reads and boots. Documentation about FIT is available at
+doc/uImage.FIT
diff --git a/doc/usage/index.rst b/doc/usage/index.rst
index 637b73c..35c515f 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -5,6 +5,7 @@
    :maxdepth: 1
 
    fdt_overlays
+   fit
    netconsole
    partitions