specifies which index to search in docs for various queries (elastic#43307)

the geo-bounding-box and phrase-suggest docs were susceptible to
failing due to other indices in the cluster. This change restricts
the queries to the index that is set up for the test.

relates to elastic#43271.

Author: talevy

docs/reference/query-dsl/geo-bounding-box-query.asciidoc

@@ -39,7 +39,7 @@ Then the following simple query can be executed with a
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -94,7 +94,7 @@ representations of the geo point, the filter can accept it as well:
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -129,7 +129,7 @@ conform with http://geojson.org/[GeoJSON].
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -157,7 +157,7 @@ Format in `lat,lon`.
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -183,7 +183,7 @@ GET /_search
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -208,7 +208,7 @@ GET /_search
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -243,7 +243,7 @@ geohash the geohash can be specified in both `top_left` and
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "geo_bounding_box" : {
@@ -273,7 +273,7 @@ values separately.
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {
@@ -323,7 +323,7 @@ are not supported. Here is an example:
 
 [source,js]
 --------------------------------------------------
-GET /_search
+GET my_locations/_search
 {
     "query": {
         "bool" : {

docs/reference/search/suggesters/phrase-suggest.asciidoc

@@ -224,7 +224,7 @@ The response contains suggestions scored by the most likely spell correction fir
 
 [source,js]
 --------------------------------------------------
-POST _search
+POST test/_search
 {
   "suggest": {
     "text" : "noble prize",
@@ -293,7 +293,7 @@ properties that can be configured.
 
 [source,js]
 --------------------------------------------------
-POST _search
+POST test/_search
 {
   "suggest": {
     "text" : "obel prize",
@@ -414,7 +414,7 @@ accept ordinary analyzer names.
 
 [source,js]
 --------------------------------------------------
-POST _search
+POST test/_search
 {
   "suggest": {
     "text" : "obel prize",