docs: riscv: convert docs to ReST and rename to *.rst

The conversion here is trivial:
 - Adjust the document title's markup
 - Do some whitespace alignment;
 - mark literal blocks;
 - Use ReST way to markup indented lists.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/Documentation/riscv/index.rst b/Documentation/riscv/index.rst
new file mode 100644
index 000000000000..c4b906d9b5a7
--- /dev/null
+++ b/Documentation/riscv/index.rst
@@ -0,0 +1,17 @@
+:orphan:
+
+===================
+RISC-V architecture
+===================
+
+.. toctree::
+    :maxdepth: 1
+
+    pmu
+
+.. only::  subproject and html
+
+   Indices
+   =======
+
+   * :ref:`genindex`