developers-guide: Add new builddep (for raspberry pi)

Add mtools

Author: mattiaswal

doc/developers-guide.md

@@ -67,7 +67,8 @@ $ sudo apt install bc binutils build-essential bzip2 cpio \
                    diffutils file findutils git gzip      \
                    libncurses-dev libssl-dev perl patch   \
                    python3 rsync sed tar unzip wget       \
-                   autopoint bison flex autoconf automake
+                   autopoint bison flex autoconf automake \
+                   mtools
 ```
 
 > For details, see the Getting Started and System Requirements sections
@@ -168,36 +169,36 @@ Now you can rebuild `confd`, just as described above, and restart Infix:
 
 ### `statd`
 
-The Infix status daemon, `src/statd`, is responsible for populating the 
-sysrepo `operational` datastore. Like `confd`, it uses XPath subscriptions, 
-but unlike `confd`, it relies entirely on `yanger`, a Python script that 
+The Infix status daemon, `src/statd`, is responsible for populating the
+sysrepo `operational` datastore. Like `confd`, it uses XPath subscriptions,
+but unlike `confd`, it relies entirely on `yanger`, a Python script that
 gathers data from local linux services and feeds it into sysrepo.
 
 To apply changes, rebuild the image:
 
     make python-statd-rebuild statd-rebuild all
 
-Rebuilding the image and testing on target for every change during 
-development process can be tedious. Instead, `yanger` allows remote 
-execution, running the script directly on the host system (test 
+Rebuilding the image and testing on target for every change during
+development process can be tedious. Instead, `yanger` allows remote
+execution, running the script directly on the host system (test
 container):
 
     infamy0:test # ../src/statd/python/yanger/yanger -x "../utils/ixll -A ssh d3a" ieee802-dot1ab-lldp
 
 `ixll` is a utility script that lets you run network commands using an
-**interface name** instead of a hostname. It makes operations like 
+**interface name** instead of a hostname. It makes operations like
 `ssh`, `scp`, and network discovery easier.
 
-Normally, `yanger` runs commands **locally** to retrieve data 
-(e.g., `lldpcli` when handling `ieee802-dot1ab-lldp`). However, when 
-executed with `-x "../utils/ixll -A ssh d3a"` it redirects these 
-commands to a remote system connected to the local `d3a` interface via 
-SSH. This setup is used for running `yanger` in an 
+Normally, `yanger` runs commands **locally** to retrieve data
+(e.g., `lldpcli` when handling `ieee802-dot1ab-lldp`). However, when
+executed with `-x "../utils/ixll -A ssh d3a"` it redirects these
+commands to a remote system connected to the local `d3a` interface via
+SSH. This setup is used for running `yanger` in an
 [interactive test environment](testing.md#interactive-usage). The yanger
-script runs on the `host` system, but key commands are executed on the 
+script runs on the `host` system, but key commands are executed on the
 `target` system.
 
-For debugging or testing, you can capture system command output and 
+For debugging or testing, you can capture system command output and
 replay it later without needing a live system.
 
 To capture:
@@ -214,9 +215,9 @@ issues without direct access to the DUT.
 ### Agree on YANG Model
 
 When making changes to the `confd` and `statd` services, you will often need to update
-the YANG models. If you are adding a new YANG module, it's best to follow the 
+the YANG models. If you are adding a new YANG module, it's best to follow the
 structure of an existing one. However, before making any changes, **always discuss
-them with the Infix core team**. This helps avoid issues later in development and 
+them with the Infix core team**. This helps avoid issues later in development and
 makes pull request reviews smoother.