Fix spelling and formatting errors in changelog

Author: rlskoeser

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 0.3
 
-- Updated to use numpy `datetime64` to support a greater range of years beyond the 4-digit years supported by python's builtin ``datetime.date`
+- Updated to use numpy `datetime64` to support a greater range of years beyond the 4-digit years supported by python's builtin `datetime.date`
   - Custom `Date` and `Timedelta` objects as shims to make numpy datetime64 and timedelta64 act more like python `datetime` objects
 - Renamed formatters to converters for more flexibility / scope
 - Support using different converters with new `format` and `parse` methods on `Undate`
@@ -11,7 +11,7 @@
   - Jupyter notebook demonstrating / validating EDTF support
     - Full support for Level 0 Date and Time Interval (no Date and Time support)
     - Level 1: 
-      - Letter-prefixed cbalendar year
+      - Letter-prefixed calendar year
       - Unspecified digit from the right
       - Partial support for extended interval
     - Level 2: unspecified digit anywhere in the date
@@ -24,7 +24,7 @@
 
 ### numpy impact
 
-Performance differences seem to be negligible, but it does increase payloud size.  The virtualenv for installing version 0.2 was 14MB; when installing the newer version with numpy, the virtualenv is 46MB (the numpy folder in site packages is 31MB on its own).
+Performance differences seem to be negligible, but it does increase payload size.  The virtualenv for installing version 0.2 was 14MB; when installing the newer version with numpy, the virtualenv is 46MB (the numpy folder in site packages is 31MB on its own).
 
 ## 0.2