Add the build doc target in Jenkins

Jenkinsfile

@@ -1,30 +1,15 @@
 pipeline {
     agent {label 'msspec_agent_amd64'}
     stages {
-        stage('Initial setup...') {
+        stage('Building the code...') {
             steps {
-                echo 'Create or update the virtual Python environment'
-            }
-        }
-
-        stage('Build the code and generate tests results...') {
-            steps {
-                echo 'building..'
-            }
-        }
-        stage('Create a setup file...') {
-            steps {
-                echo 'creating Python pip file...'
-            }
-        }
-        stage('Test installation...') {
-            steps {
-                echo 'testing the install process...'
+                echo 'make devel'
             }
         }
         stage('Building HTML documentation...') {
             steps {
                 echo 'building HTML...'
+                source _venv/bin/activate && pip install sphinx lxml && cd doc && make html
             }
         }
         stage('Syncing website...') {