docs: fix liquid syntax errors (#2592)

For liquid text processor double braces `{{` `}}`
are special chars for templating.
Since we use them in some of our docs with different purpose,
we must escape them to avoid syntax errors from liquid.

For escaping curly braces we use bult-in plugin which helps
to enclose sections of text via `{% raw %}` and `{% endraw %}`.
This approach prevents liquid syntax errors and makes render correct.

Signed-off-by: hagen1778 <roman@victoriametrics.com>

app/vmalert/README.md

@@ -197,6 +197,7 @@ set the path via `-rule.templates` flag.
 
 For example, template `grafana.filter` can be defined as following:
 
+{% raw  %}
 ```
 {{ define "grafana.filter" -}}
   {{- $labels := .arg0 -}}
@@ -207,9 +208,11 @@ For example, template `grafana.filter` can be defined as following:
   {{- end -}}
 {{- end -}}
 ```
+{% endraw %}
 
 And then used in annotations:
 
+{% raw  %}
 ```yaml
 groups:
   - name: AlertGroupName
@@ -223,6 +226,7 @@ groups:
         annotations:
           dashboard: '{{ $externalURL }}/d/dashboard?orgId=1{{ template "grafana.filter" (args .CommonLabels "account_id" "any_label") }}'
 ```
+{% endraw %}
 
 The `-rule.templates` flag supports wildcards so multiple files with templates can be loaded.
 The content of `-rule.templates` can be also [hot reloaded](#hot-config-reload).

docs/PerTenantStatistic.md

@@ -60,6 +60,7 @@ to prevent limits exhaustion.
 
 Here is an alert example for high churn rate by the tenant:
 
+{% raw  %}
 ```yaml
 
 - alert: TooHighChurnRate
@@ -79,3 +80,4 @@ Here is an alert example for high churn rate by the tenant:
             High Churn Rate is tightly connected with database performance and may
             result in unexpected OOM's or slow queries."
 ```
+{% endraw %}

docs/operator/quick-start.MD

@@ -752,6 +752,7 @@ kubectl logs vmalert-example-vmalert-6f8748c6f9-hcfrr vmalert
 
 Let's add simple rule for `VMAlert` itself, `delta(vmalert_config_last_reload_errors_total[5m]) > 1`
 
+{% raw %}
 ```yaml
 cat << 'EOF' | kubectl apply -f -
 apiVersion: operator.victoriametrics.com/v1beta1
@@ -775,6 +776,7 @@ spec:
             description: 'error reloading vmalert config, reload count for 5 min {{ $value }}'
 EOF
 ```
+{% endraw %}
 
  Ensure, that new alert was started:
  ```bash
@@ -790,6 +792,7 @@ kubectl logs vmalert-example-vmalert-6f8748c6f9-hcfrr vmalert
 
  Let's trigger it by adding some incorrect rule
  
+{% raw %}
 ```yaml
 cat << 'EOF' | kubectl apply -f -
 apiVersion: operator.victoriametrics.com/v1beta1
@@ -811,6 +814,7 @@ spec:
             value: "{{ $badValue | bad function }}"
 EOF
 ```
+{% endraw %}
 
 `VMAlert` will report incorrect rule config and fire alert:
 ```bash
@@ -1129,6 +1133,7 @@ vmauth-config-example   Opaque   1      2m32s
 ```
 
  Generated configuration can be retrieved with command:
+{% raw %}
 ```text
 kubectl get secrets/vmauth-config-example -o=go-template='{{index .data "config.yaml.gz"}}' | base64 -d | gunzip
 
@@ -1136,6 +1141,7 @@ users:
 - url_prefix: http://localhost:8428
   bearer_token: some-default-token
 ```
+{% endraw %}
 
   Operator generates default config, if `VMUser`s for given `VMAuth` wasn't found.
 

docs/vmalert.md

@@ -201,6 +201,7 @@ set the path via `-rule.templates` flag.
 
 For example, template `grafana.filter` can be defined as following:
 
+{% raw  %}
 ```
 {{ define "grafana.filter" -}}
   {{- $labels := .arg0 -}}
@@ -211,9 +212,11 @@ For example, template `grafana.filter` can be defined as following:
   {{- end -}}
 {{- end -}}
 ```
+{% endraw %}
 
 And then used in annotations:
 
+{% raw  %}
 ```yaml
 groups:
   - name: AlertGroupName
@@ -227,6 +230,7 @@ groups:
         annotations:
           dashboard: '{{ $externalURL }}/d/dashboard?orgId=1{{ template "grafana.filter" (args .CommonLabels "account_id" "any_label") }}'
 ```
+{% endraw %}
 
 The `-rule.templates` flag supports wildcards so multiple files with templates can be loaded.
 The content of `-rule.templates` can be also [hot reloaded](#hot-config-reload).