docs: Fix minor issues with the docs. (#3389)

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>

docs/configuration/configuration.md

@@ -12,17 +12,17 @@ configuration file defines everything related to scraping [jobs and their
 instances](https://prometheus.io/docs/concepts/jobs_instances/), as well as
 which [rule files to load](recording_rules.md#configuring-rules).
 
-To view all available command-line flags, run `prometheus -h`.
+To view all available command-line flags, run `./prometheus -h`.
 
 Prometheus can reload its configuration at runtime. If the new configuration
 is not well-formed, the changes will not be applied.
 A configuration reload is triggered by sending a `SIGHUP` to the Prometheus process or
-sending a HTTP POST request to the `/-/reload` endpoint.
+sending a HTTP POST request to the `/-/reload` endpoint (when the `--web.enable-lifecycle` flag is enabled).
 This will also reload any configured rule files.
 
 ## Configuration file
 
-To specify which configuration file to load, use the `-config.file` flag.
+To specify which configuration file to load, use the `--config.file` flag.
 
 The file is written in [YAML format](http://en.wikipedia.org/wiki/YAML),
 defined by the scheme described below.

docs/configuration/recording_rules.md

@@ -32,9 +32,8 @@ When the file is syntactically valid, the checker prints a textual
 representation of the parsed rules to standard output and then exits with
 a `0` return status.
 
-If there are any syntax errors, it prints an error message to standard error
-and exits with a `1` return status. On invalid input arguments the exit status
-is `2`.
+If there are any syntax errors or invalid input arguments, it prints an error 
+message to standard error and exits with a `1` return status.
 
 ## Recording rules
 

docs/configuration/template_examples.md

@@ -13,16 +13,17 @@ data, etc. The Prometheus templating language is based on the
 
 ## Simple alert field templates
 
-    ALERT InstanceDown
-      IF up == 0
-      FOR 5m
-      LABELS {
-        severity="page"
-      }
-      ANNOTATIONS {
-        summary = "Instance {{$labels.instance}} down",
-        description = "{{$labels.instance}} of job {{$labels.job}} has been down for more than 5 minutes.",
-      }
+```
+alert: InstanceDown
+expr: up == 0
+for: 5m
+labels:
+  - severity: page
+  
+annotations:
+  - summary: "Instance {{$labels.instance}} down"
+  - description: "{{$labels.instance}} of job {{$labels.job}} has been down for more than 5 minutes."
+```
 
 Alert field templates will be executed during every rule iteration for each
 alert that fires, so keep any queries and templates lightweight. If you have a

docs/getting_started.md

@@ -119,11 +119,11 @@ For more about the expression language, see the
 To graph expressions, navigate to http://localhost:9090/graph and use the "Graph"
 tab.
 
-For example, enter the following expression to graph the per-second rate of all
-storage chunk operations happening in the self-scraped Prometheus:
+For example, enter the following expression to graph the per-second rate of chunks 
+being created in the self-scraped Prometheus:
 
 ```
-rate(prometheus_local_storage_chunk_ops_total[1m])
+rate(prometheus_tsdb_head_chunks_created_total[1m])
 ```
 
 Experiment with the graph range parameters and other settings.