[damned-lies] chore: transfer dependencies to the host system

[Guillaume Bernard <gbernard src gnome org>]

commit 375bc0892fa31bd63e1d150570dcc93288f54941
Author: Guillaume Bernard <associations guillaume-bernard fr>
Date:   Mon May 9 15:06:20 2022 +0200

    chore: transfer dependencies to the host system
    
    Some dependencies are removed from the requirements.txt file as we
    now recommend to install them on the host system that runs the
    application. In a containered system, this will prevent compilation and
    reduce CPU/bandwidth usage.

 CONTRIBUTING.md  | 13 ++++++++-----
 requirements.txt | 12 +++++++-----
 2 files changed, 15 insertions(+), 10 deletions(-)
---
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d7443b53..4d31303f 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -89,24 +89,27 @@ To run properly on any system, `damned-lies` requires some libraries and softwar
   the `xml2po` program.
 - **MariaDB client library**: the underlying library that is used through Python to connect to a 
MySQL/MariaDB instance.
 - **ICU library**:  internationalization libraries of the Unicode Consortium.
-- **Development tools**: used to compile some other dependencies listed in `requirements.txt`, just as 
`pillow`.
+- **Development tools**: used to compile some other dependencies, just as `pillow` if you install it using 
`pip`.
 
 You can install them on your operating system using the following command line examples:
 
 * On **Debian** based systems:
   ```bash
-  apt install gettext intltool gnome-doc-utils itstool libmariadbclient-dev libicu-dev libxml2-dev 
python3-dev yelp-tools build-essential
+  apt install gettext intltool gnome-doc-utils itstool libmariadbclient-dev python3-icu python3-pillow 
python3-mysqldb libicu-dev libxml2-dev python3-dev yelp-tools build-essential
   ```
 * On **Fedora** based systems:
   ```
-  dnf install gettext intltool gnome-doc-utils itstool mariadb-devel libicu-devel libxml2-devel python-devel 
yelp-tools @development-tools
+  dnf install gettext intltool gnome-doc-utils itstool mariadb-devel python3-pyicu python3-pillow 
python3-mysqlclient python3-mysl libicu-devel libxml2-devel python-devel yelp-tools @development-tools
   ```
 
 ## Python environment
 
 Once libraries are installed on your OS, the recommended method to run `damned-lies` is to use
-a [virtual environment](https://docs.python.org/en/3/library/venv.html). Python dependencies are listed in
-the `requirements.txt` file.
+a [virtual environment](https://docs.python.org/en/3/library/venv.html). Python dependencies are listed in 
the
+`requirements.txt` file. If you did not install all dependencies on your host system (like `pyicu`, 
`pillow`, etc.)
+you should install them manually. There are still listed in the `requirements.txt` file.
+
+There are development specific dependencies in `requirements-dev.txt` you might also want to install.
 
 ### Optional requirements
 
diff --git a/requirements.txt b/requirements.txt
index 6a5edc3c..4ff2de70 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,8 @@
-django>=3.2,<4.1
-mysqlclient  # MySQL database connector
-pillow  # Hackergotchi check
-markdown==3.2.2  # Team presentation markup rendering
-pyicu==2.3.1  # Correct sorting in various languages. 2.4.2 fails to compile on some platforms
+django~=4.0
+markdown~=3.2.2  # Team presentation markup rendering
 translate-toolkit>=2.2.0
+
+# Dependencies that might be installed on your system
+# mysqlclient  # MySQL database connector
+# pyicu  # Correct sorting in various languages. 2.4.2 fails to compile on some platforms
+# pillow  # Hackergotchi check