[DOCS] EQL: Add collapsible sections to EQL tutorial docs (#56235)

Adds collapsible sections to the snippet examples of the EQL tutorial
docs.

Also adds a leading slash to EQL API snippet examples.

docs/reference/eql/eql-search-api.asciidoc

@@ -16,7 +16,7 @@ In {es}, EQL assumes each document in an index corresponds to an event.
 ////
 [source,console]
 ----
-PUT my_index/_bulk?refresh
+PUT /my_index/_bulk?refresh
 {"index":{"_index" : "my_index", "_id" : "1"}}
 { "@timestamp": "2020-12-06T11:04:05.000Z", "agent": { "id": "8a4f500d" }, "event": { "category": "process" }, "process": { "name": "cmd.exe", "path": "C:\\Windows\\System32\\cmd.exe" } }
 {"index":{"_index" : "my_index", "_id" : "2"}}
@@ -44,9 +44,9 @@ GET my_index/_eql/search
 [[eql-search-api-request]]
 ==== {api-request-title}
 
-`GET <index>/_eql/search`
+`GET /<index>/_eql/search`
 
-`POST <index>/_eql/search`
+`POST /<index>/_eql/search`
 
 [[eql-search-api-prereqs]]
 ==== {api-prereq-title}

docs/reference/eql/search.asciidoc

@@ -6,8 +6,13 @@
 experimental::[]
 
 To start using EQL in {es}, first ensure your event data meets
-<<eql-requirements,EQL requirements>>. Then ingest or add the data to an {es}
+<<eql-requirements,EQL requirements>>. You can then use the <<eql-search-api,EQL
-index.
+search API>> to search event data stored in one or more {es} indices.
+
+.*Example*
+[%collapsible]
+====
+To get started, ingest or add the data to an {es} index.
 
 The following <<docs-bulk,bulk API>> request adds some example log data to the
 `sec_logs` index. This log data follows the {ecs-ref}[Elastic Common Schema
@@ -15,7 +20,7 @@ The following <<docs-bulk,bulk API>> request adds some example log data to the
 
 [source,console]
 ----
-PUT sec_logs/_bulk?refresh
+PUT /sec_logs/_bulk?refresh
 {"index":{"_index" : "sec_logs", "_id" : "1"}}
 { "@timestamp": "2020-12-06T11:04:05.000Z", "agent": { "id": "8a4f500d" }, "event": { "category": "process" }, "process": { "name": "cmd.exe", "path": "C:\\Windows\\System32\\cmd.exe" } }
 {"index":{"_index" : "sec_logs", "_id" : "2"}}
@@ -30,13 +35,13 @@ PUT sec_logs/_bulk?refresh
 // TESTSETUP
 
 [TIP]
-====
+=====
 You also can set up {beats-ref}/getting-started.html[{beats}], such as
 {auditbeat-ref}/auditbeat-getting-started.html[{auditbeat}] or
 {winlogbeat-ref}/winlogbeat-getting-started.html[{winlogbeat}], to automatically
 send and index your event data in {es}. See
 {beats-ref}/getting-started.html[Getting started with {beats}].
-====
+=====
 
 You can now use the EQL search API to search this index using an EQL query.
 
@@ -46,7 +51,7 @@ specified in the `query` parameter. The EQL query matches events with an
 
 [source,console]
 ----
-GET sec_logs/_eql/search
+GET /sec_logs/_eql/search
 {
   "query": """
     process where process.name == "cmd.exe"
@@ -122,6 +127,7 @@ https://en.wikipedia.org/wiki/Unix_time[Unix epoch], in ascending order.
 }
 ----
 // TESTRESPONSE[s/"took": 60/"took": $body.took/]
+====
 
 [discrete]
 [[eql-search-specify-event-category-field]]
@@ -131,12 +137,15 @@ The EQL search API uses `event.category` as the required
 <<eql-required-fields,event category field>> by default. You can use the
 `event_category_field` parameter to specify another event category field.
 
-For example, the following request specifies `file.type` as the event category
+.*Example*
+[%collapsible]
+====
+The following request specifies `file.type` as the event category
 field.
 
 [source,console]
 ----
-GET sec_logs/_eql/search
+GET /sec_logs/_eql/search
 {
    "event_category_field": "file.type",
   "query": """
@@ -144,6 +153,7 @@ GET sec_logs/_eql/search
   """
 }
 ----
+====
 
 [discrete]
 [[eql-search-specify-timestamp-field]]
@@ -153,12 +163,15 @@ The EQL search API uses `@timestamp` as the required <<eql-required-fields,event
 timestamp field>> by default. You can use the `timestamp_field` parameter to
 specify another timestamp field.
 
-For example, the following request specifies `file.accessed` as the event
+.*Example*
+[%collapsible]
+====
+The following request specifies `file.accessed` as the event
 timestamp field.
 
 [source,console]
 ----
-GET sec_logs/_eql/search
+GET /sec_logs/_eql/search
 {
   "timestamp_field": "file.accessed",
   "query": """
@@ -166,23 +179,27 @@ GET sec_logs/_eql/search
   """
 }
 ----
+====
 
 [discrete]
 [[eql-search-filter-query-dsl]]
 === Filter using query DSL
 
-You can use the `filter` parameter to specify an additional query using
+You can use the EQL search API's `filter` parameter to specify an additional
-<<query-dsl,query DSL>>. This query filters the documents on which the EQL query
+query using <<query-dsl,query DSL>>. This query filters the documents on which
-runs.
+the EQL query runs.
 
-For example, the following request uses a `range` query to filter the `sec_logs`
+.*Example*
+[%collapsible]
+====
+The following request uses a `range` query to filter the `sec_logs`
 index down to only documents with a `file.size` value greater than `1` but less
 than `1000000` bytes. The EQL query in `query` parameter then runs on these
 filtered documents.
 
 [source,console]
 ----
-GET sec_logs/_eql/search
+GET /sec_logs/_eql/search
 {
   "filter": {
     "range" : {
@@ -197,3 +214,4 @@ GET sec_logs/_eql/search
   """
 }
 ----
+====