[PATCH] docs: hint about creating a new virtual environment for major upgrades

[Thomas De Schampheleire]

# HG changeset patch
# User Thomas De Schampheleire <thomas.de_schampheleire at nokia.com>
# Date 1552247908 -3600
#      Sun Mar 10 20:58:28 2019 +0100
# Node ID e487f7977a4e452ccdf034afb576f5d88ced1e6f
# Parent  9f41dc6f328adc06b71b7304f54a164f955fd056
docs: hint about creating a new virtual environment for major upgrades

While not strictly necessary, it may be interesting to start from a new
virtualenv rather than upgrading inside the old one. This will remove old
packages once installed manually but no longer necessary. At the same time,
it makes a rollback of the upgrade process more easy.

Hint about it in the upgrade documentation.

diff --git a/docs/upgrade.rst b/docs/upgrade.rst
--- a/docs/upgrade.rst
+++ b/docs/upgrade.rst
@@ -71,6 +71,12 @@ This will list all packages installed in
 Kallithea isn't listed, activate the correct virtual environment.
 See the appropriate installation page for details.
 
+.. note::
+    Alternatively, you could also create a new virtual environment. This could
+    particularly be interesting for major upgrades of Kallithea. See the
+    appropriate installation page for details. After creating and activating the
+    new virtual environment, proceed with the rest of the upgrade process as
+    detailed below.
 
 4. Install new version of Kallithea
 -----------------------------------