fix notation used for keywords

Author: paryoja

SPEC.md

@@ -46,12 +46,12 @@ possible experience, with relevant helper APIs, documentation and tutorials.
 
 Indexes are managed by `IndexLogEntry` which consists of 
 
-* name: Name of the index.
-* derivedDataset: Data that has been derived from one or more datasets and may be optionally used by 
+* `name`: Name of the index.
+* `derivedDataset`: Data that has been derived from one or more datasets and may be optionally used by 
 an arbitrary query optimizer to improve the speed of data retrieval.
-* content: File contents used by the index.
-* source: Data source.
-* properties: Hash map for managing properties of the index. 
+* `content`: File contents used by the index.
+* `source`: Data source.
+* `properties`: Hash map for managing properties of the index. 
 
 Indexes can have the following states:
 * Stable states
@@ -110,7 +110,7 @@ Available modes:
 
 A user can drop an existing index by using the deleteIndex API and providing the index name.
 Index deletion is a soft-delete operation i.e., only the index's status in the Hyperspace metadata from is changed 
-from "ACTIVE" to "DELETED". This will exclude the deleted index from any future query optimization and Hyperspace 
+from `ACTIVE` to `DELETED`. This will exclude the deleted index from any future query optimization and Hyperspace 
 no longer picks that index for any query. However, index files for a deleted index still remain available 
 (since it is a soft-delete), so if you accidentally deleted the index, you could still restore it.
 
@@ -131,20 +131,20 @@ This will bring back the latest version of index into ACTIVE status and makes it
 ### Cancel
 
 Cancel API to bring back index from an inconsistent state to the last known stable state. 
-E.g. if index fails during creation, in "CREATING" state. 
+E.g. if index fails during creation, in `CREATING` state. 
 The index will not allow any index modifying operations unless a cancel is called.
 
-> Note: Cancel from "VACUUMING" state will move it forward to "DOESNOTEXIST" state. 
+> Note: Cancel from `VACUUMING` state will move it forward to `DOESNOTEXIST` state. 
 
-> Note: If no previous stable state exists, cancel will move it to "DOESNOTEXIST" state.
+> Note: If no previous stable state exists, cancel will move it to `DOESNOTEXIST` state.
 
 
 # Index Type
 
 Hyperspace provides several index types.
 
 * Covering Index
-  * Roughly speaking, index data for CoveringIndex is just a vertical
+  * Roughly speaking, index data for `CoveringIndex` is just a vertical
     slice of the source data, including only the indexed and included columns,
     bucketed and sorted by the indexed columns for efficient access.
 * Data Skipping Index
@@ -182,7 +182,7 @@ automatically if it is applicable.
 ## Explain
 
 Explains how indexes will be applied to the given dataframe.
-Explain API from Hyperspace is very similar to Spark's df.explain API but allows users to compare their original plan 
+Explain API from Hyperspace is very similar to Spark's `df.explain` API but allows users to compare their original plan 
 vs the updated index-dependent plan before running their query. 
 You have an option to choose from html/plaintext/console mode to display the command output.