Replace composite index by two indexes for FTS (#394)

Co-authored-by: Pratim <[email protected]>

versioned_docs/version-1.0.x/reference-guide/full-text-search.mdx

@@ -51,9 +51,9 @@ Your text field won't be "full text searchable" unless you define a [full-text
 Depending on the use case, each field can be associated with a different analyser. 
 
 ```surql
--- Defining a full-text index on the 'title' and 'content' field of the 'book' table
-DEFINE INDEX book_idx ON book FIELDS title, content SEARCH ANALYZER 
-custom_analyzer BM25;
+-- Defining two full-text indexes on the 'title' and 'content' field of the 'book' table
+DEFINE INDEX book_title ON book FIELDS title SEARCH ANALYZER custom_analyzer BM25;
+DEFINE INDEX book_content ON book FIELDS content SEARCH ANALYZER custom_analyzer BM25;
 ```
 
 ## The MATCHES Operator

versioned_docs/version-1.1.x/reference-guide/full-text-search.mdx

@@ -50,9 +50,9 @@ To make a text field searchable, you need to set up a [full-text index](/docs/su
 Depending on the use case, each field can be associated with a different analyser. 
 
 ```surql
--- Defining a full-text index on the 'title' and 'content' field of the 'book' table
-DEFINE INDEX book_idx ON book FIELDS title, content SEARCH ANALYZER 
-custom_analyzer BM25;
+-- Defining two full-text indexes on the 'title' and 'content' field of the 'book' table
+DEFINE INDEX book_title ON book FIELDS title SEARCH ANALYZER custom_analyzer BM25;
+DEFINE INDEX book_content ON book FIELDS content SEARCH ANALYZER custom_analyzer BM25;
 ```
 
 ## The MATCHES Operator

versioned_docs/version-1.2.x/reference-guide/full-text-search.mdx

@@ -51,9 +51,9 @@ To make a text field searchable, you need to set up a [full-text index](/docs/su
 Depending on the use case, each field can be associated with a different analyser. 
 
 ```surql
--- Defining a full-text index on the 'title' and 'content' field of the 'book' table
-DEFINE INDEX book_idx ON book FIELDS title, content SEARCH ANALYZER 
-custom_analyzer BM25;
+-- Defining two full-text indexes on the 'title' and 'content' field of the 'book' table
+DEFINE INDEX book_title ON book FIELDS title SEARCH ANALYZER custom_analyzer BM25;
+DEFINE INDEX book_content ON book FIELDS content SEARCH ANALYZER custom_analyzer BM25;
 ```
 
 ## The MATCHES Operator

versioned_docs/version-nightly/reference-guide/full-text-search.mdx

@@ -50,9 +50,9 @@ To make a text field searchable, you need to set up a [full-text index](/docs/su
 Depending on the use case, each field can be associated with a different analyser. 
 
 ```surql
--- Defining a full-text index on the 'title' and 'content' field of the 'book' table
-DEFINE INDEX book_idx ON book FIELDS title, content SEARCH ANALYZER 
-custom_analyzer BM25;
+-- Defining two full-text indexes on the 'title' and 'content' field of the 'book' table
+DEFINE INDEX book_title ON book FIELDS title SEARCH ANALYZER custom_analyzer BM25;
+DEFINE INDEX book_content ON book FIELDS content SEARCH ANALYZER custom_analyzer BM25;
 ```
 
 ## The MATCHES Operator