Cleanup code / move small changes in pug files to Dockerfile (login.pug/share.pug) and use ARG (variables to set text in them)

ldap-overleaf-sl/sharelatex/login.pug

@@ -1,43 +0,0 @@
-extends ../layout
-
-block vars
-  - metadata = { viewport: true }
-
-block content
-  .content.content-alt
-    .container
-      .row
-        .col-md-6.col-md-offset-3.col-lg-4.col-lg-offset-4
-          .card
-            .page-header
-              h1 #{translate("log_in")}
-            form(async-form="login", name="loginForm", action='/login', method="POST", ng-cloak)
-              input(name='_csrf', type='hidden', value=csrfToken)
-              form-messages(for="loginForm")
-              .form-group
-                input.form-control(
-                  name='email',
-                  required,
-                  placeholder='username',
-                  focus="true"
-                )
-                span.small.text-primary(ng-show="loginForm.email.$invalid && loginForm.email.$dirty")
-                  | #{translate("must_be_email_address")}
-              .form-group
-                input.form-control(
-                  type='password',
-                  name='password',
-                  required,
-                  placeholder='********',
-                  ng-model="password"
-                )
-                span.small.text-primary(ng-show="loginForm.password.$invalid && loginForm.password.$dirty")
-                  | #{translate("required")}
-              .actions
-                button.btn-primary.btn(
-                  type='submit',
-                  ng-disabled="loginForm.inflight"
-                )
-                  span(ng-show="!loginForm.inflight") #{translate("login")}
-                  span(ng-show="loginForm.inflight") #{translate("logging_in")}...
-