👌 IMPROVE: Add prepend_text for codes (#71)

Optional key, to define additional `prepend_text`.
This is in preparation for adding conda env activation.

tasks/aiida-code.yml

@@ -8,6 +8,7 @@
       folder: "{{ code_params.folder }}"
       plugin: "{{ code_params.plugin }}"
       description: "{{ plugin.key }} {{ code_params.name }}, original plugin version {{ plugin.value.version }}, executable version {{ code_params.version }}"
+      prepend_text: "{{ code_params.prepend_text | default('') }}"
   loop: "{{ lookup('vars', plugin.value.codes_var) }}"
   loop_control:
     loop_var: code_params

templates/code.yml

@@ -4,4 +4,6 @@ input_plugin: "{{ aiida_code.plugin }}"
 on_computer: true
 remote_abs_path: "{{ aiida_code.folder |  regex_replace('\\$\\{HOME}', current_user_home) }}/{{ aiida_code.executable }}"
 computer: "{{ aiida_computer_name }}"
-prepend_text: "ulimit -s unlimited"
+prepend_text: |
+  ulimit -s unlimited
+  {{ aiida_code.prepend_text | indent(width=2) }}