Update BUILD-INSTRUCTIONS-LINUX.md

Minor edits to Linux build instructions.

docs/BUILD-INSTRUCTIONS-LINUX.md

@@ -7,11 +7,21 @@ gLabels Linux Build Instructions
 - g++
 - CMake 3.22+
 - Qt6 6.2+ Development Packages ( Qt6Core, Qt6Widgets, Qt6PrintSupport, Qt6Xml, Qt6Svg, Qt6Test )
-- zlib 1.2+ Development Package
+
 
 > Even if the above library packages are installed, their corresponding development packages
 > may also need to be installed.  Development packages are usually named something like
-> libraryName-dev or libraryName-devel.
+> libraryName-dev or libraryName-devel.  Also, package names can vary significantly between
+> distributions as well as between versions of the same distribution.  Finding the exact package
+> names for your particular distribution, may require some trial-and-error and googling.
+
+#### Optional Dependencies
+
+- zlib 1.2+ Development Package
+- gnu barcode 0.98+ (Distributions do not always install the `barcode.h` file needed for external projects)
+- libqrencode 3.4= Development Package
+- libzint 2.15+
+
 
 ### Compile and Install
 
@@ -32,8 +42,14 @@ $ sudo make install
 ### Installing Prerequisites
 ```
 $ sudo apt install cmake
-$ sudo apt install qt6-base-dev qt6-svg-dev qt6-tools-dev zlib1g-dev
+$ sudo apt install qt6-base-dev qt6-svg-dev qt6-tools-dev
 ```
+
+_ZLib (Optional)_
+```
+$ sudo apt install zlib1g-dev
+```
+
 _QREncode (Optional)_
 ```
 $ sudo apt install pkgconf libqrencode-dev
@@ -42,12 +58,12 @@ _Zint (Optional)_
 
 Install zint from source:
 ```
-wget https://downloads.sourceforge.net/project/zint/zint/2.15.0/zint-2.15.0-src.tar.gz
-tar xzf zint-2.15.0-src.tar.gz
-cd zint-2.15.0-src/
-mkdir build && cd build && cmake .. && make
-sudo make install
-sudo ldconfig
+$ wget https://downloads.sourceforge.net/project/zint/zint/2.15.0/zint-2.15.0-src.tar.gz
+$ tar xzf zint-2.15.0-src.tar.gz
+$ cd zint-2.15.0-src/
+$ mkdir build && cd build && cmake .. && make
+$ sudo make install
+$ sudo ldconfig
 ```
 
 _GNU Barcode (Optional)_
@@ -55,6 +71,7 @@ _GNU Barcode (Optional)_
 ```
 $ sudo apt install barcode
 ```
+
 ### Compile and Install gLabels
 
 ```
@@ -76,7 +93,7 @@ We assume the build system already has things like cmake and the GNU C++ suite i
 $ sudo dnf install qt5-qtbase-devel qt5-qtsvg-devel qt5-linguist qt5-qttools
 ```
 These installs will pull in additional packages to fill out their prerequisites.
-Fedora has a different package naming scheme that Ubuntu. This is to distinguish the QT6
+Fedora has a different package naming scheme than Ubuntu. This is to distinguish the QT6
 packages from the QT3 and QT4 packages that they still support for compatibility.
 If the Cmake pass or build has missing package errors or warnings, you can search for the needed
 package with:
@@ -93,4 +110,4 @@ $ cmake ..
 $ make
 $ sudo make install
 
-```
+```