add fix filter/corotate to some administrative files

doc/src/fixes.txt

@@ -42,6 +42,7 @@ Fixes :h1
    fix_eos_table_rx
    fix_evaporate
    fix_external
+   fix_filter_corotate
    fix_flow_gauss
    fix_freeze
    fix_gcmc

doc/src/lammps.book

@@ -168,6 +168,7 @@ fix_eos_table.html
 fix_eos_table_rx.html
 fix_evaporate.html
 fix_external.html
+fix_filter_corotate.html
 fix_flow_gauss.html
 fix_freeze.html
 fix_gcmc.html

src/.gitignore

@@ -328,6 +328,8 @@
 /fix_eos_table.h
 /fix_evaporate.cpp
 /fix_evaporate.h
+/fix_filter_corotate.cpp
+/fix_filter_corotate.h
 /fix_viscosity.cpp
 /fix_viscosity.h
 /fix_ehex.cpp