Add 'lowdown' to build dependencies so GitHub actions actually runs it

Building the man page is optional and happens automatically if command
'lowdown' is present on the system. Add it to the Snap definition and to
all GitHub CI files so man page conversion will be tested and fully used.

.github/workflows/cmake-freebsd.yml

@@ -33,8 +33,7 @@ jobs:
         with:
           release: '14.0'
           usesh: true
-          prepare: pkg install -y cmake ninja
+          prepare: pkg install -y cmake ninja lowdown
           run: |
             CXX=clang++ cmake -B build -G Ninja -DBTOP_STATIC=ON
             cmake --build build --verbose
-

.github/workflows/cmake-linux.yml

@@ -30,11 +30,10 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Install build tools
-        run: apk add --no-cache --update clang cmake lld ninja
+        run: apk add --no-cache --update clang cmake lld ninja lowdown
 
       - name: Configure
         run: CXX=clang++ LDFLAGS=-fuse-ld=lld cmake -B build -G Ninja -DBTOP_STATIC=ON
 
       - name: Compile
         run: cmake --build build --verbose
-

.github/workflows/cmake-macos.yml

@@ -32,7 +32,7 @@ jobs:
         run: |
           export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1
           brew update --quiet
-          brew install --force --overwrite cmake llvm@17 ninja
+          brew install --force --overwrite cmake llvm@17 ninja lowdown
 
       - name: Configure
         run: |
@@ -44,4 +44,3 @@ jobs:
 
       - name: Compile
         run: cmake --build build --verbose
-

.github/workflows/continuous-build-freebsd.yml

@@ -45,7 +45,7 @@ jobs:
           release: '14.0'
           usesh: true
           prepare: |
-            pkg install -y gmake gcc coreutils git
+            pkg install -y gmake gcc coreutils git lowdown
             git config --global --add safe.directory /home/runner/work/btop/btop
           run: |
             CXX=${{ matrix.compiler }} gmake STATIC=true STRIP=true
@@ -59,4 +59,3 @@ jobs:
           name: btop-x86_64-freebsd-14
           path: 'bin/*'
           if-no-files-found: error
-

.github/workflows/continuous-build-gpu.yml

@@ -42,4 +42,3 @@ jobs:
 
       - name: Compile
         run: make CXX=g++ GPU_SUPPORT=true
-

.github/workflows/continuous-build-linux.yml

@@ -89,7 +89,7 @@ jobs:
 
     steps:
       - name: Install build tools
-        run: apk add --no-cache coreutils git make tar zstd
+        run: apk add --no-cache coreutils git make tar zstd lowdown
 
       - name: Fix - Unsafe repository stop
         run: git config --global --add safe.directory /__w/btop/btop

.github/workflows/continuous-build-openbsd.yml

@@ -42,7 +42,7 @@ jobs:
           release: '7.4'
           usesh: true
           prepare: |
-            pkg_add gmake gcc%11 g++%11 coreutils git
+            pkg_add gmake gcc%11 g++%11 coreutils git lowdown
             git config --global --add safe.directory /home/runner/work/btop/btop
           run: |
             gmake CXX=eg++ STATIC=true STRIP=true
@@ -55,4 +55,3 @@ jobs:
           name: btop-x86_64-openbsd-7.4
           path: 'bin/*'
           if-no-files-found: error
-

snap/snapcraft.yaml

@@ -56,7 +56,8 @@ parts:
       - build-essential
       - gcc-11
       - g++-11
-
+      - lowdown
+
     override-pull: |
       snapcraftctl pull
       snapcraftctl set-version "$(git describe --tags | sed 's/^v//' | cut -d "-" -f1)"