add release notes for v2.0

Author: alistairewj

website/content/about/releasenotes.md

@@ -17,7 +17,20 @@ This page lists changes implemented in sequential updates to the eICU Collaborat
 
 # Current version
 
-The current version of the database is v1.2. When referencing this version, we recommend using the full title: eICU Collaborative Research Database v1.2.
+The current version of the database is v2.0. When referencing this version, we recommend using the full title: eICU Collaborative Research Database v2.0.
+
+# eICU Collaborative Research Database v2.0
+
+The eICU Collaboratvie Research Database v2.0 was released on 17 May 2018. This was a major release which involved a schema change, potentially breaking compatibility with existing code.
+
+Changes include:
+
+* #68: The medication table had the following modifications: `drugname` and `dosage` can now be NULL. Frequency of administration has been added in a new column called `frequency`.
+* #69: In all tables columns which had a suffix of `time`, `time24`, and `year` were removed, *except* for a single instance in the patient table. These columns were redundant and can be easily rederived if needed using offsets and joining to the patient table.
+* #70: Ten tables have been added to the public release. They are: customLab, intakeOutput, microLab, note, nurseAssessment, nurseCare, nurseCharting, physicalExam, respiratoryCare, respiratoryCharting. Documentation of these tables is available online.
+* #71: Hospitals which do not have any corresponding patient admissions have been removed from the hospital table.
+
+In addition, the website now contains Jupyter notebooks for each table which highlight potential usage of the data.
 
 # eICU Collaborative Research Database v1.2