Update Index template loading guide to use the correct endpoint (#29869…

…) (#29877)

This PR updates the documentation for loading index templates manually. The endpoint used in the documentation was outdated. That lead to some confusion.

(cherry picked from commit 055798a)

Co-authored-by: Noémi Ványi <kvch@users.noreply.github.com>

libbeat/docs/howto/load-index-templates.asciidoc

@@ -294,7 +294,7 @@ ifdef::deb_os,rpm_os[]
 
 ["source","sh",subs="attributes"]
 ----
-curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_template/{beatname_lc}-{version} -d@{beatname_lc}.template.json
+curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_index_template/{beatname_lc}-{version} -d@{beatname_lc}.template.json
 ----
 endif::deb_os,rpm_os[]
 
@@ -303,7 +303,7 @@ ifdef::mac_os[]
 
 ["source","sh",subs="attributes"]
 ----
-curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_template/{beatname_lc}-{version} -d@{beatname_lc}.template.json
+curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_index_template/{beatname_lc}-{version} -d@{beatname_lc}.template.json
 ----
 endif::mac_os[]
 
@@ -312,7 +312,7 @@ ifdef::linux_os[]
 
 ["source","sh",subs="attributes"]
 ----
-curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_template/{beatname_lc}-{version} -d@{beatname_lc}.template.json
+curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_index_template/{beatname_lc}-{version} -d@{beatname_lc}.template.json
 ----
 endif::linux_os[]
 
@@ -323,6 +323,6 @@ endif::win_only[]
 
 ["source","sh",subs="attributes"]
 ----
-PS > Invoke-RestMethod -Method Put -ContentType "application/json" -InFile {beatname_lc}.template.json -Uri http://localhost:9200/_template/{beatname_lc}-{version}
+PS > Invoke-RestMethod -Method Put -ContentType "application/json" -InFile {beatname_lc}.template.json -Uri http://localhost:9200/_index_template/{beatname_lc}-{version}
 ----
 endif::win_os[]

libbeat/docs/upgrading.asciidoc

@@ -330,7 +330,7 @@ layer. See <<enable-ecs-compatibility>>.
 +
 ["source","sh",subs="attributes"]
 ----
-DELETE /_template/metricbeat-{version}
+DELETE /_index_template/metricbeat-{version}
 ----
 +
 Because the index template was loaded without the compatibility layer enabled,