[vala/0.48] docs: Bump vala version references in README.md

[Rico Tzschichholz <ricotz src gnome org>]

commit 9bec91a3598f316539293399104b1b992ae31bac
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sat Sep 25 15:35:42 2021 +0200

    docs: Bump vala version references in README.md

 README.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/README.md b/README.md
index 50c67601e..e9222db68 100644
--- a/README.md
+++ b/README.md
@@ -87,10 +87,10 @@ https://gitlab.gnome.org/Archive/vala-bootstrap
 
 
 Here is an example on how to download and compile from a Vala release tarball.
-In this example it is release version 0.42.3:
+In this example it is release version 0.48.19:
 
 ```sh
-curl --silent --show-error --location https://download.gnome.org/sources/vala/0.42/vala-0.42.3.tar.xz 
--output vala-bootstrap.tar.xz
+curl --silent --show-error --location https://download.gnome.org/sources/vala/0.48/vala-0.48.19.tar.xz 
--output vala-bootstrap.tar.xz
 tar --extract --file vala-bootstrap.tar.xz
 cd vala-bootstrap
 ./configure --prefix=/opt/vala-bootstrap
@@ -144,10 +144,10 @@ git clean -dfx
 make && sudo make install
 ```
 
-If you wish to build a specific release, for example 0.40.11:
+If you wish to build a specific release, for example 0.54.1:
 
 ```sh
-git checkout 0.40.11
+git checkout 0.54.1
 git clean -dfx
 ./autogen.sh
 make && sudo make install